diff --git a/web/chat/chat-input-bar.react.js b/web/chat/chat-input-bar.react.js
--- a/web/chat/chat-input-bar.react.js
+++ b/web/chat/chat-input-bar.react.js
@@ -40,7 +40,6 @@
 import {
   type ClientThreadJoinRequest,
   type ThreadJoinPayload,
-  type LegacyThreadInfo,
 } from 'lib/types/thread-types.js';
 import { type UserInfos } from 'lib/types/user-types.js';
 import {
@@ -67,7 +66,7 @@
 } from '../utils/typeahead-utils.js';
 
 type BaseProps = {
-  +threadInfo: LegacyThreadInfo | ThreadInfo,
+  +threadInfo: ThreadInfo,
   +inputState: InputState,
 };
 type Props = {
@@ -83,7 +82,7 @@
   +joinThread: (request: ClientThreadJoinRequest) => Promise<ThreadJoinPayload>,
   +typeaheadMatchedStrings: ?TypeaheadMatchedStrings,
   +suggestions: $ReadOnlyArray<MentionTypeaheadSuggestionItem>,
-  +parentThreadInfo: ?LegacyThreadInfo | ?ThreadInfo,
+  +parentThreadInfo: ?ThreadInfo,
 };
 
 class ChatInputBar extends React.PureComponent<Props> {
diff --git a/web/chat/chat-message-list.react.js b/web/chat/chat-message-list.react.js
--- a/web/chat/chat-message-list.react.js
+++ b/web/chat/chat-message-list.react.js
@@ -28,7 +28,6 @@
 import type { FetchMessageInfosPayload } from 'lib/types/message-types.js';
 import type { ThreadInfo } from 'lib/types/minimally-encoded-thread-permissions-types.js';
 import { threadTypes } from 'lib/types/thread-types-enum.js';
-import type { LegacyThreadInfo } from 'lib/types/thread-types.js';
 import {
   type DispatchActionPromise,
   useDispatchActionPromise,
@@ -56,7 +55,7 @@
 const editBoxTopMargin = 10;
 
 type BaseProps = {
-  +threadInfo: LegacyThreadInfo | ThreadInfo,
+  +threadInfo: ThreadInfo,
 };
 
 type Props = {
diff --git a/web/chat/composed-message.react.js b/web/chat/composed-message.react.js
--- a/web/chat/composed-message.react.js
+++ b/web/chat/composed-message.react.js
@@ -13,7 +13,6 @@
 import { getMessageLabel } from 'lib/shared/edit-messages-utils.js';
 import { assertComposableMessageType } from 'lib/types/message-types.js';
 import type { ThreadInfo } from 'lib/types/minimally-encoded-thread-permissions-types.js';
-import type { LegacyThreadInfo } from 'lib/types/thread-types.js';
 
 import { getComposedMessageID } from './chat-constants.js';
 import css from './chat-message-list.css';
@@ -51,7 +50,7 @@
 
 type BaseProps = {
   +item: ChatMessageInfoItem,
-  +threadInfo: LegacyThreadInfo | ThreadInfo,
+  +threadInfo: ThreadInfo,
   +shouldDisplayPinIndicator: boolean,
   +sendFailed: boolean,
   +children: React.Node,
diff --git a/web/chat/edit-message-provider.js b/web/chat/edit-message-provider.js
--- a/web/chat/edit-message-provider.js
+++ b/web/chat/edit-message-provider.js
@@ -6,7 +6,6 @@
 import ModalOverlay from 'lib/components/modal-overlay.react.js';
 import type { ChatMessageInfoItem } from 'lib/selectors/chat-selectors.js';
 import type { ThreadInfo } from 'lib/types/minimally-encoded-thread-permissions-types.js';
-import type { LegacyThreadInfo } from 'lib/types/thread-types';
 
 import { EditTextMessage } from './edit-text-message.react.js';
 
@@ -19,7 +18,7 @@
 
 export type EditState = {
   +messageInfo: ChatMessageInfoItem,
-  +threadInfo: LegacyThreadInfo | ThreadInfo,
+  +threadInfo: ThreadInfo,
   +editedMessageDraft: ?string,
   +isError: boolean,
   +position?: ModalPosition,
diff --git a/web/chat/edit-text-message.react.js b/web/chat/edit-text-message.react.js
--- a/web/chat/edit-text-message.react.js
+++ b/web/chat/edit-text-message.react.js
@@ -9,7 +9,6 @@
 import { useEditMessage } from 'lib/shared/edit-messages-utils.js';
 import { trimMessage } from 'lib/shared/message-utils.js';
 import type { ThreadInfo } from 'lib/types/minimally-encoded-thread-permissions-types.js';
-import type { LegacyThreadInfo } from 'lib/types/thread-types.js';
 
 import { editBoxBottomRowHeight } from './chat-constants.js';
 import ChatInputTextArea from './chat-input-text-area.react.js';
@@ -21,7 +20,7 @@
 
 type Props = {
   +item: ChatMessageInfoItem,
-  +threadInfo: LegacyThreadInfo | ThreadInfo,
+  +threadInfo: ThreadInfo,
   +background: boolean,
 };
 
diff --git a/web/chat/failed-send.react.js b/web/chat/failed-send.react.js
--- a/web/chat/failed-send.react.js
+++ b/web/chat/failed-send.react.js
@@ -12,7 +12,6 @@
   type RawComposableMessageInfo,
 } from 'lib/types/message-types.js';
 import type { ThreadInfo } from 'lib/types/minimally-encoded-thread-permissions-types.js';
-import type { LegacyThreadInfo } from 'lib/types/thread-types.js';
 
 import css from './chat-message-list.css';
 import multimediaMessageSendFailed from './multimedia-message-send-failed.js';
@@ -23,13 +22,13 @@
 
 type BaseProps = {
   +item: ChatMessageInfoItem,
-  +threadInfo: LegacyThreadInfo | ThreadInfo,
+  +threadInfo: ThreadInfo,
 };
 type Props = {
   ...BaseProps,
   +rawMessageInfo: RawComposableMessageInfo,
   +inputState: ?InputState,
-  +parentThreadInfo: ?LegacyThreadInfo | ?ThreadInfo,
+  +parentThreadInfo: ?ThreadInfo,
 };
 class FailedSend extends React.PureComponent<Props> {
   retryingText = false;
diff --git a/web/chat/message.react.js b/web/chat/message.react.js
--- a/web/chat/message.react.js
+++ b/web/chat/message.react.js
@@ -6,7 +6,6 @@
 import { type ChatMessageInfoItem } from 'lib/selectors/chat-selectors.js';
 import { messageTypes } from 'lib/types/message-types-enum.js';
 import type { ThreadInfo } from 'lib/types/minimally-encoded-thread-permissions-types.js';
-import type { LegacyThreadInfo } from 'lib/types/thread-types.js';
 import { longAbsoluteDate } from 'lib/utils/date-utils.js';
 
 import css from './chat-message-list.css';
@@ -18,7 +17,7 @@
 
 type Props = {
   +item: ChatMessageInfoItem,
-  +threadInfo: LegacyThreadInfo | ThreadInfo,
+  +threadInfo: ThreadInfo,
   +shouldDisplayPinIndicator: boolean,
 };
 function Message(props: Props): React.Node {
diff --git a/web/chat/multimedia-message.react.js b/web/chat/multimedia-message.react.js
--- a/web/chat/multimedia-message.react.js
+++ b/web/chat/multimedia-message.react.js
@@ -10,7 +10,6 @@
 import { type ChatMessageInfoItem } from 'lib/selectors/chat-selectors.js';
 import { messageTypes } from 'lib/types/message-types-enum.js';
 import type { ThreadInfo } from 'lib/types/minimally-encoded-thread-permissions-types.js';
-import type { LegacyThreadInfo } from 'lib/types/thread-types.js';
 
 import css from './chat-message-list.css';
 import ComposedMessage from './composed-message.react.js';
@@ -20,7 +19,7 @@
 
 type BaseProps = {
   +item: ChatMessageInfoItem,
-  +threadInfo: LegacyThreadInfo | ThreadInfo,
+  +threadInfo: ThreadInfo,
   +shouldDisplayPinIndicator: boolean,
 };
 type Props = {
diff --git a/web/chat/pinned-messages-banner.react.js b/web/chat/pinned-messages-banner.react.js
--- a/web/chat/pinned-messages-banner.react.js
+++ b/web/chat/pinned-messages-banner.react.js
@@ -5,7 +5,6 @@
 
 import { useModalContext } from 'lib/components/modal-provider.react.js';
 import type { ThreadInfo } from 'lib/types/minimally-encoded-thread-permissions-types.js';
-import type { LegacyThreadInfo } from 'lib/types/thread-types.js';
 import { pinnedMessageCountText } from 'lib/utils/message-pinning-utils.js';
 
 import css from './pinned-messages-banner.css';
@@ -13,7 +12,7 @@
 import PinnedMessagesModal from '../modals/chat/pinned-messages-modal.react.js';
 
 type Props = {
-  +threadInfo: LegacyThreadInfo | ThreadInfo,
+  +threadInfo: ThreadInfo,
 };
 
 function PinnedMessagesBanner(props: Props): React.Node {
diff --git a/web/chat/robotext-message.react.js b/web/chat/robotext-message.react.js
--- a/web/chat/robotext-message.react.js
+++ b/web/chat/robotext-message.react.js
@@ -35,7 +35,7 @@
 
 type Props = {
   +item: RobotextChatMessageInfoItem,
-  +threadInfo: LegacyThreadInfo | ThreadInfo,
+  +threadInfo: ThreadInfo,
 };
 function RobotextMessage(props: Props): React.Node {
   let inlineEngagement;
diff --git a/web/chat/text-message.react.js b/web/chat/text-message.react.js
--- a/web/chat/text-message.react.js
+++ b/web/chat/text-message.react.js
@@ -9,7 +9,6 @@
 import { onlyEmojiRegex } from 'lib/shared/emojis.js';
 import { messageTypes } from 'lib/types/message-types-enum.js';
 import type { ThreadInfo } from 'lib/types/minimally-encoded-thread-permissions-types.js';
-import type { LegacyThreadInfo } from 'lib/types/thread-types.js';
 
 import css from './chat-message-list.css';
 import ComposedMessage from './composed-message.react.js';
@@ -19,7 +18,7 @@
 
 type Props = {
   +item: ChatMessageInfoItem,
-  +threadInfo: LegacyThreadInfo | ThreadInfo,
+  +threadInfo: ThreadInfo,
   +shouldDisplayPinIndicator: boolean,
 };
 function TextMessage(props: Props): React.Node {
diff --git a/web/chat/thread-menu.react.js b/web/chat/thread-menu.react.js
--- a/web/chat/thread-menu.react.js
+++ b/web/chat/thread-menu.react.js
@@ -18,7 +18,6 @@
 import type { ThreadInfo } from 'lib/types/minimally-encoded-thread-permissions-types.js';
 import { threadPermissions } from 'lib/types/thread-permission-types.js';
 import { threadTypes } from 'lib/types/thread-types-enum.js';
-import type { LegacyThreadInfo } from 'lib/types/thread-types.js';
 import { useDispatchActionPromise } from 'lib/utils/redux-promise-utils.js';
 
 import css from './thread-menu.css';
@@ -36,7 +35,7 @@
 import { useSelector } from '../redux/redux-utils.js';
 
 type ThreadMenuProps = {
-  +threadInfo: LegacyThreadInfo | ThreadInfo,
+  +threadInfo: ThreadInfo,
 };
 
 function ThreadMenu(props: ThreadMenuProps): React.Node {
diff --git a/web/chat/thread-top-bar.react.js b/web/chat/thread-top-bar.react.js
--- a/web/chat/thread-top-bar.react.js
+++ b/web/chat/thread-top-bar.react.js
@@ -6,7 +6,6 @@
 import SWMansionIcon from 'lib/components/SWMansionIcon.react.js';
 import { threadIsPending } from 'lib/shared/thread-utils.js';
 import type { ThreadInfo } from 'lib/types/minimally-encoded-thread-permissions-types.js';
-import type { LegacyThreadInfo } from 'lib/types/thread-types.js';
 import { useResolvedThreadInfo } from 'lib/utils/entity-helpers.js';
 
 import PinnedMessagesBanner from './pinned-messages-banner.react.js';
@@ -18,7 +17,7 @@
 import MessageSearchModal from '../modals/search/message-search-modal.react.js';
 
 type ThreadTopBarProps = {
-  +threadInfo: LegacyThreadInfo | ThreadInfo,
+  +threadInfo: ThreadInfo,
 };
 function ThreadTopBar(props: ThreadTopBarProps): React.Node {
   const { threadInfo } = props;
diff --git a/web/components/message-result.react.js b/web/components/message-result.react.js
--- a/web/components/message-result.react.js
+++ b/web/components/message-result.react.js
@@ -7,7 +7,6 @@
 import { useStringForUser } from 'lib/hooks/ens-cache.js';
 import type { ChatMessageInfoItem } from 'lib/selectors/chat-selectors.js';
 import type { ThreadInfo } from 'lib/types/minimally-encoded-thread-permissions-types.js';
-import type { LegacyThreadInfo } from 'lib/types/thread-types.js';
 import { longAbsoluteDate } from 'lib/utils/date-utils.js';
 
 import css from './message-result.css';
@@ -17,7 +16,7 @@
 
 type MessageResultProps = {
   +item: ChatMessageInfoItem,
-  +threadInfo: LegacyThreadInfo | ThreadInfo,
+  +threadInfo: ThreadInfo,
   +scrollable: boolean,
 };
 
diff --git a/web/input/input-state-container.react.js b/web/input/input-state-container.react.js
--- a/web/input/input-state-container.react.js
+++ b/web/input/input-state-container.react.js
@@ -636,8 +636,8 @@
               this.cancelPendingUpload(threadID, localUploadID),
             sendTextMessage: (
               messageInfo: RawTextMessageInfo,
-              threadInfo: LegacyThreadInfo | ThreadInfo,
-              parentThreadInfo: ?LegacyThreadInfo | ?ThreadInfo,
+              threadInfo: ThreadInfo,
+              parentThreadInfo: ?ThreadInfo,
             ) =>
               this.sendTextMessage(messageInfo, threadInfo, parentThreadInfo),
             createMultimediaMessage: (
@@ -1244,8 +1244,8 @@
 
   async sendTextMessage(
     messageInfo: RawTextMessageInfo,
-    inputThreadInfo: LegacyThreadInfo | ThreadInfo,
-    parentThreadInfo: ?LegacyThreadInfo | ?ThreadInfo,
+    inputThreadInfo: ThreadInfo,
+    parentThreadInfo: ?ThreadInfo,
   ) {
     this.props.sendCallbacks.forEach(callback => callback());
 
diff --git a/web/input/input-state.js b/web/input/input-state.js
--- a/web/input/input-state.js
+++ b/web/input/input-state.js
@@ -70,8 +70,8 @@
   +cancelPendingUpload: (localUploadID: string) => void,
   +sendTextMessage: (
     messageInfo: RawTextMessageInfo,
-    threadInfo: LegacyThreadInfo | ThreadInfo,
-    parentThreadInfo: ?LegacyThreadInfo | ?ThreadInfo,
+    threadInfo: ThreadInfo,
+    parentThreadInfo: ?ThreadInfo,
   ) => mixed,
   +createMultimediaMessage: (
     localID: number,
diff --git a/web/modals/chat/pinned-messages-modal.react.js b/web/modals/chat/pinned-messages-modal.react.js
--- a/web/modals/chat/pinned-messages-modal.react.js
+++ b/web/modals/chat/pinned-messages-modal.react.js
@@ -19,7 +19,6 @@
 } from 'lib/shared/message-utils.js';
 import type { RawMessageInfo } from 'lib/types/message-types.js';
 import type { ThreadInfo } from 'lib/types/minimally-encoded-thread-permissions-types.js';
-import type { LegacyThreadInfo } from 'lib/types/thread-types.js';
 import { pinnedMessageCountText } from 'lib/utils/message-pinning-utils.js';
 import { useDispatchActionPromise } from 'lib/utils/redux-promise-utils.js';
 
@@ -30,7 +29,7 @@
 import Modal from '../modal.react.js';
 
 type Props = {
-  +threadInfo: LegacyThreadInfo | ThreadInfo,
+  +threadInfo: ThreadInfo,
 };
 
 const loadingStatusSelector = createLoadingStatusSelector(
diff --git a/web/modals/chat/sidebar-promote-modal.react.js b/web/modals/chat/sidebar-promote-modal.react.js
--- a/web/modals/chat/sidebar-promote-modal.react.js
+++ b/web/modals/chat/sidebar-promote-modal.react.js
@@ -3,7 +3,6 @@
 import * as React from 'react';
 
 import type { ThreadInfo } from 'lib/types/minimally-encoded-thread-permissions-types.js';
-import type { LegacyThreadInfo } from 'lib/types/thread-types.js';
 import { useResolvedThreadInfo } from 'lib/utils/entity-helpers.js';
 
 import css from './sidebar-promote-modal.css';
@@ -13,7 +12,7 @@
 type Props = {
   +onClose: () => void,
   +onConfirm: () => void,
-  +threadInfo: LegacyThreadInfo | ThreadInfo,
+  +threadInfo: ThreadInfo,
 };
 
 function SidebarPromoteModal(props: Props): React.Node {
diff --git a/web/modals/chat/toggle-pin-modal.react.js b/web/modals/chat/toggle-pin-modal.react.js
--- a/web/modals/chat/toggle-pin-modal.react.js
+++ b/web/modals/chat/toggle-pin-modal.react.js
@@ -12,7 +12,6 @@
 import { modifyItemForResultScreen } from 'lib/shared/message-utils.js';
 import type { RawMessageInfo } from 'lib/types/message-types.js';
 import type { ThreadInfo } from 'lib/types/minimally-encoded-thread-permissions-types.js';
-import type { LegacyThreadInfo } from 'lib/types/thread-types.js';
 import { useDispatchActionPromise } from 'lib/utils/redux-promise-utils.js';
 
 import css from './toggle-pin-modal.css';
@@ -22,7 +21,7 @@
 
 type TogglePinModalProps = {
   +item: ChatMessageInfoItem,
-  +threadInfo: LegacyThreadInfo | ThreadInfo,
+  +threadInfo: ThreadInfo,
 };
 
 function TogglePinModal(props: TogglePinModalProps): React.Node {
diff --git a/web/modals/search/message-search-modal.react.js b/web/modals/search/message-search-modal.react.js
--- a/web/modals/search/message-search-modal.react.js
+++ b/web/modals/search/message-search-modal.react.js
@@ -5,7 +5,6 @@
 import { useModalContext } from 'lib/components/modal-provider.react.js';
 import type { ChatMessageInfoItem } from 'lib/selectors/chat-selectors.js';
 import type { ThreadInfo } from 'lib/types/minimally-encoded-thread-permissions-types.js';
-import type { LegacyThreadInfo } from 'lib/types/thread-types.js';
 import { useResolvedThreadInfo } from 'lib/utils/entity-helpers.js';
 
 import css from './message-search-modal.css';
@@ -19,7 +18,7 @@
 import Modal from '../modal.react.js';
 
 type ContentProps = {
-  +threadInfo: LegacyThreadInfo | ThreadInfo,
+  +threadInfo: ThreadInfo,
 };
 
 function MessageSearchModal(props: ContentProps): React.Node {
diff --git a/web/modals/threads/confirm-leave-thread-modal.react.js b/web/modals/threads/confirm-leave-thread-modal.react.js
--- a/web/modals/threads/confirm-leave-thread-modal.react.js
+++ b/web/modals/threads/confirm-leave-thread-modal.react.js
@@ -3,7 +3,6 @@
 import * as React from 'react';
 
 import type { ThreadInfo } from 'lib/types/minimally-encoded-thread-permissions-types.js';
-import type { LegacyThreadInfo } from 'lib/types/thread-types.js';
 import { useResolvedThreadInfo } from 'lib/utils/entity-helpers.js';
 
 import css from './confirm-leave-thread-modal.css';
@@ -11,7 +10,7 @@
 import Modal from '../modal.react.js';
 
 type Props = {
-  +threadInfo: LegacyThreadInfo | ThreadInfo,
+  +threadInfo: ThreadInfo,
   +onClose: () => void,
   +onConfirm: () => void,
 };
diff --git a/web/modals/threads/create/compose-subchannel-modal.react.js b/web/modals/threads/create/compose-subchannel-modal.react.js
--- a/web/modals/threads/create/compose-subchannel-modal.react.js
+++ b/web/modals/threads/create/compose-subchannel-modal.react.js
@@ -9,7 +9,6 @@
 import { createLoadingStatusSelector } from 'lib/selectors/loading-selectors.js';
 import type { ThreadInfo } from 'lib/types/minimally-encoded-thread-permissions-types.js';
 import { threadTypes } from 'lib/types/thread-types-enum.js';
-import type { LegacyThreadInfo } from 'lib/types/thread-types.js';
 import { useResolvedThreadInfo } from 'lib/utils/entity-helpers.js';
 import { useDispatchActionPromise } from 'lib/utils/redux-promise-utils.js';
 import { useDispatch } from 'lib/utils/redux-utils.js';
@@ -27,7 +26,7 @@
 
 type Props = {
   +onClose: () => void,
-  +parentThreadInfo: LegacyThreadInfo | ThreadInfo,
+  +parentThreadInfo: ThreadInfo,
 };
 
 const getThreadType = (visibility: VisibilityType, announcement: boolean) => {
diff --git a/web/modals/threads/create/steps/subchannel-members.react.js b/web/modals/threads/create/steps/subchannel-members.react.js
--- a/web/modals/threads/create/steps/subchannel-members.react.js
+++ b/web/modals/threads/create/steps/subchannel-members.react.js
@@ -5,14 +5,13 @@
 import { useUserSearchIndex } from 'lib/selectors/nav-selectors.js';
 import { useAncestorThreads } from 'lib/shared/ancestor-threads.js';
 import type { ThreadInfo } from 'lib/types/minimally-encoded-thread-permissions-types.js';
-import type { LegacyThreadInfo } from 'lib/types/thread-types.js';
 
 import MembersList from './subchannel-members-list.react.js';
 import css from './subchannel-members.css';
 import Search from '../../../../components/search.react.js';
 
 type SubchannelMembersProps = {
-  +parentThreadInfo: LegacyThreadInfo | ThreadInfo,
+  +parentThreadInfo: ThreadInfo,
   +selectedUsers: $ReadOnlySet<string>,
   +searchText: string,
   +setSearchText: string => void,
diff --git a/web/modals/threads/thread-picker-modal.react.js b/web/modals/threads/thread-picker-modal.react.js
--- a/web/modals/threads/thread-picker-modal.react.js
+++ b/web/modals/threads/thread-picker-modal.react.js
@@ -6,7 +6,6 @@
 import { useGlobalThreadSearchIndex } from 'lib/selectors/nav-selectors.js';
 import { onScreenEntryEditableThreadInfos } from 'lib/selectors/thread-selectors.js';
 import type { ThreadInfo } from 'lib/types/minimally-encoded-thread-permissions-types.js';
-import type { LegacyThreadInfo } from 'lib/types/thread-types.js';
 import { useResolvedThreadInfo } from 'lib/utils/entity-helpers.js';
 
 import css from './thread-picker-modal.css';
@@ -17,7 +16,7 @@
 import Modal, { type ModalOverridableProps } from '../modal.react.js';
 
 type OptionProps = {
-  +threadInfo: LegacyThreadInfo | ThreadInfo,
+  +threadInfo: ThreadInfo,
   +createNewEntry: (threadID: string) => void,
   +onCloseModal: () => void,
 };
diff --git a/web/navigation-panels/chat-thread-ancestors.react.js b/web/navigation-panels/chat-thread-ancestors.react.js
--- a/web/navigation-panels/chat-thread-ancestors.react.js
+++ b/web/navigation-panels/chat-thread-ancestors.react.js
@@ -6,13 +6,12 @@
 
 import { useAncestorThreads } from 'lib/shared/ancestor-threads.js';
 import type { ThreadInfo } from 'lib/types/minimally-encoded-thread-permissions-types.js';
-import type { LegacyThreadInfo } from 'lib/types/thread-types.js';
 import { useResolvedThreadInfo } from 'lib/utils/entity-helpers.js';
 
 import css from './chat-thread-ancestors.css';
 
 type ThreadAncestorsProps = {
-  +threadInfo: LegacyThreadInfo | ThreadInfo,
+  +threadInfo: ThreadInfo,
 };
 function ThreadAncestors(props: ThreadAncestorsProps): React.Node {
   const { threadInfo } = props;
diff --git a/web/navigation-panels/nav-state-info-bar.react.js b/web/navigation-panels/nav-state-info-bar.react.js
--- a/web/navigation-panels/nav-state-info-bar.react.js
+++ b/web/navigation-panels/nav-state-info-bar.react.js
@@ -4,14 +4,13 @@
 import * as React from 'react';
 
 import type { ThreadInfo } from 'lib/types/minimally-encoded-thread-permissions-types.js';
-import type { LegacyThreadInfo } from 'lib/types/thread-types.js';
 
 import ThreadAncestors from './chat-thread-ancestors.react.js';
 import css from './nav-state-info-bar.css';
 import ThreadAvatar from '../avatars/thread-avatar.react.js';
 
 type NavStateInfoBarProps = {
-  +threadInfo: LegacyThreadInfo | ThreadInfo,
+  +threadInfo: ThreadInfo,
 };
 function NavStateInfoBar(props: NavStateInfoBarProps): React.Node {
   const { threadInfo } = props;
@@ -27,7 +26,7 @@
 }
 
 type PossiblyEmptyNavStateInfoBarProps = {
-  +threadInfoInput: ?LegacyThreadInfo | ?ThreadInfo,
+  +threadInfoInput: ?ThreadInfo,
 };
 function PossiblyEmptyNavStateInfoBar(
   props: PossiblyEmptyNavStateInfoBarProps,
diff --git a/web/selectors/chat-selectors.js b/web/selectors/chat-selectors.js
--- a/web/selectors/chat-selectors.js
+++ b/web/selectors/chat-selectors.js
@@ -15,7 +15,7 @@
 import { threadIsPending } from 'lib/shared/thread-utils.js';
 import type { MessageInfo, MessageStore } from 'lib/types/message-types.js';
 import type { ThreadInfo } from 'lib/types/minimally-encoded-thread-permissions-types.js';
-import type { LegacyThreadInfo, SidebarInfo } from 'lib/types/thread-types.js';
+import type { SidebarInfo } from 'lib/types/thread-types.js';
 
 import type { AppState } from '../redux/redux-setup.js';
 import { useSelector } from '../redux/redux-utils.js';
@@ -30,12 +30,12 @@
     sidebarInfoSelector,
     (
       threadInfos: {
-        +[id: string]: LegacyThreadInfo | ThreadInfo,
+        +[id: string]: ThreadInfo,
       },
       messageStore: MessageStore,
       messageInfos: { +[id: string]: ?MessageInfo },
       activeChatThreadID: ?string,
-      pendingThreadInfo: ?LegacyThreadInfo | ?ThreadInfo,
+      pendingThreadInfo: ?ThreadInfo,
       sidebarInfos: { +[id: string]: $ReadOnlyArray<SidebarInfo> },
     ): ?ChatThreadItem => {
       if (!activeChatThreadID) {
@@ -58,9 +58,7 @@
     },
   );
 
-function useChatThreadItem(
-  threadInfo: ?LegacyThreadInfo | ?ThreadInfo,
-): ?ChatThreadItem {
+function useChatThreadItem(threadInfo: ?ThreadInfo): ?ChatThreadItem {
   const messageInfos = useSelector(messageInfoSelector);
   const sidebarInfos = useSelector(sidebarInfoSelector);
   const messageStore = useSelector(state => state.messageStore);
diff --git a/web/tooltips/tooltip-action-utils.js b/web/tooltips/tooltip-action-utils.js
--- a/web/tooltips/tooltip-action-utils.js
+++ b/web/tooltips/tooltip-action-utils.js
@@ -19,7 +19,6 @@
 import { messageTypes } from 'lib/types/message-types-enum.js';
 import type { ThreadInfo } from 'lib/types/minimally-encoded-thread-permissions-types.js';
 import { threadPermissions } from 'lib/types/thread-permission-types.js';
-import type { LegacyThreadInfo } from 'lib/types/thread-types.js';
 import { longAbsoluteDate } from 'lib/utils/date-utils.js';
 import { canToggleMessagePin } from 'lib/utils/message-pinning-utils.js';
 
@@ -130,7 +129,7 @@
 
 function useMessageTooltipSidebarAction(
   item: ChatMessageInfoItem,
-  threadInfo: LegacyThreadInfo | ThreadInfo,
+  threadInfo: ThreadInfo,
 ): ?MessageTooltipAction {
   const { threadCreatedFromMessage, messageInfo } = item;
   const { popModal } = useModalContext();
@@ -172,7 +171,7 @@
 
 function useMessageTooltipReplyAction(
   item: ChatMessageInfoItem,
-  threadInfo: LegacyThreadInfo | ThreadInfo,
+  threadInfo: ThreadInfo,
 ): ?MessageTooltipAction {
   const { messageInfo } = item;
   const { popModal } = useModalContext();
@@ -237,7 +236,7 @@
 
 function useMessageReactAction(
   item: ChatMessageInfoItem,
-  threadInfo: LegacyThreadInfo | ThreadInfo,
+  threadInfo: ThreadInfo,
 ): ?MessageTooltipAction {
   const { messageInfo } = item;
 
@@ -272,7 +271,7 @@
 
 function useMessageTogglePinAction(
   item: ChatMessageInfoItem,
-  threadInfo: LegacyThreadInfo | ThreadInfo,
+  threadInfo: ThreadInfo,
 ): ?MessageTooltipAction {
   const { pushModal } = useModalContext();
   const { messageInfo, isPinned } = item;
@@ -308,7 +307,7 @@
 
 function useMessageEditAction(
   item: ChatMessageInfoItem,
-  threadInfo: LegacyThreadInfo | ThreadInfo,
+  threadInfo: ThreadInfo,
 ): ?MessageTooltipAction {
   const { messageInfo } = item;
 
@@ -351,7 +350,7 @@
 
 function useMessageTooltipActions(
   item: ChatMessageInfoItem,
-  threadInfo: LegacyThreadInfo | ThreadInfo,
+  threadInfo: ThreadInfo,
 ): $ReadOnlyArray<MessageTooltipAction> {
   const sidebarAction = useMessageTooltipSidebarAction(item, threadInfo);
   const replyAction = useMessageTooltipReplyAction(item, threadInfo);
@@ -388,7 +387,7 @@
 type UseMessageTooltipArgs = {
   +availablePositions: $ReadOnlyArray<TooltipPosition>,
   +item: ChatMessageInfoItem,
-  +threadInfo: LegacyThreadInfo | ThreadInfo,
+  +threadInfo: ThreadInfo,
 };
 
 function useMessageTooltip({
diff --git a/web/types/nav-types.js b/web/types/nav-types.js
--- a/web/types/nav-types.js
+++ b/web/types/nav-types.js
@@ -4,7 +4,6 @@
 
 import type { ThreadInfo } from 'lib/types/minimally-encoded-thread-permissions-types.js';
 import { type BaseNavInfo } from 'lib/types/nav-types.js';
-import type { LegacyThreadInfo } from 'lib/types/thread-types.js';
 import { legacyThreadInfoValidator } from 'lib/types/thread-types.js';
 import {
   type AccountUserInfo,
@@ -34,7 +33,7 @@
   ...$Exact<BaseNavInfo>,
   +tab: NavigationTab,
   +activeChatThreadID: ?string,
-  +pendingThread?: LegacyThreadInfo | ThreadInfo,
+  +pendingThread?: ThreadInfo,
   +settingsSection?: NavigationSettingsSection,
   +selectedUserList?: $ReadOnlyArray<AccountUserInfo>,
   +chatMode?: NavigationChatMode,
diff --git a/web/utils/thread-utils.js b/web/utils/thread-utils.js
--- a/web/utils/thread-utils.js
+++ b/web/utils/thread-utils.js
@@ -12,7 +12,6 @@
 } from 'lib/shared/thread-utils.js';
 import type { ThreadInfo } from 'lib/types/minimally-encoded-thread-permissions-types.js';
 import { threadTypes } from 'lib/types/thread-types-enum.js';
-import type { LegacyThreadInfo } from 'lib/types/thread-types.js';
 import type { AccountUserInfo } from 'lib/types/user-types.js';
 
 import { useSelector } from '../redux/redux-utils.js';
@@ -40,7 +39,7 @@
 
 function useThreadInfoForPossiblyPendingThread(
   activeChatThreadID: ?string,
-): ?LegacyThreadInfo | ?ThreadInfo {
+): ?ThreadInfo {
   const { isChatCreation, selectedUserInfos } = useInfosForPendingThread();
 
   const loggedInUserInfo = useLoggedInUserInfo();