diff --git a/lib/shared/messages/add-members-message-spec.js b/lib/shared/messages/add-members-message-spec.js
--- a/lib/shared/messages/add-members-message-spec.js
+++ b/lib/shared/messages/add-members-message-spec.js
@@ -2,12 +2,13 @@
 
 import invariant from 'invariant';
 
-import type {
-  CreateMessageInfoParams,
-  MessageSpec,
-  NotificationTextsParams,
-  MergeRobotextMessageItemResult,
-  ShowInMessagePreviewParams,
+import {
+  type CreateMessageInfoParams,
+  type MessageSpec,
+  type NotificationTextsParams,
+  type MergeRobotextMessageItemResult,
+  type ShowInMessagePreviewParams,
+  messageNotifyTypes,
 } from './message-spec.js';
 import { joinResult } from './utils.js';
 import type { RobotextChatMessageInfoItem } from '../../selectors/chat-selectors.js';
@@ -25,6 +26,7 @@
 import type { ThreadInfo } from '../../types/minimally-encoded-thread-permissions-types.js';
 import type { NotifTexts } from '../../types/notif-types.js';
 import { threadTypeIsThick } from '../../types/thread-types-enum.js';
+import { threadIDIsThick } from '../../types/thread-types.js';
 import type { RelativeUserInfo } from '../../types/user-types.js';
 import {
   type EntityText,
@@ -236,4 +238,9 @@
     messageInfo: AddMembersMessageInfo | RawAddMembersMessageInfo,
     params: ShowInMessagePreviewParams,
   ) => (threadTypeIsThick(params.threadInfo.type) ? messageInfo.time : null),
+
+  getMessageNotifyType: async (rawMessageInfo: RawAddMembersMessageInfo) =>
+    threadIDIsThick(rawMessageInfo.threadID)
+      ? messageNotifyTypes.SET_UNREAD
+      : messageNotifyTypes.NONE,
 });
diff --git a/lib/shared/messages/join-thread-message-spec.js b/lib/shared/messages/join-thread-message-spec.js
--- a/lib/shared/messages/join-thread-message-spec.js
+++ b/lib/shared/messages/join-thread-message-spec.js
@@ -2,11 +2,12 @@
 
 import invariant from 'invariant';
 
-import type {
-  MessageSpec,
-  RobotextParams,
-  MergeRobotextMessageItemResult,
-  ShowInMessagePreviewParams,
+import {
+  type MessageSpec,
+  type RobotextParams,
+  type MergeRobotextMessageItemResult,
+  type ShowInMessagePreviewParams,
+  messageNotifyTypes,
 } from './message-spec.js';
 import { joinResult } from './utils.js';
 import type { RobotextChatMessageInfoItem } from '../../selectors/chat-selectors.js';
@@ -24,6 +25,7 @@
 import type { ThreadInfo } from '../../types/minimally-encoded-thread-permissions-types.js';
 import type { NotifTexts } from '../../types/notif-types.js';
 import { threadTypeIsThick } from '../../types/thread-types-enum.js';
+import { threadIDIsThick } from '../../types/thread-types.js';
 import type { RelativeUserInfo } from '../../types/user-types.js';
 import {
   type EntityText,
@@ -182,4 +184,9 @@
     messageInfo: JoinThreadMessageInfo | RawJoinThreadMessageInfo,
     params: ShowInMessagePreviewParams,
   ) => (threadTypeIsThick(params.threadInfo.type) ? messageInfo.time : null),
+
+  getMessageNotifyType: async (rawMessageInfo: RawJoinThreadMessageInfo) =>
+    threadIDIsThick(rawMessageInfo.threadID)
+      ? messageNotifyTypes.SET_UNREAD
+      : messageNotifyTypes.NONE,
 });
diff --git a/lib/shared/messages/leave-thread-message-spec.js b/lib/shared/messages/leave-thread-message-spec.js
--- a/lib/shared/messages/leave-thread-message-spec.js
+++ b/lib/shared/messages/leave-thread-message-spec.js
@@ -2,11 +2,12 @@
 
 import invariant from 'invariant';
 
-import type {
-  MessageSpec,
-  RobotextParams,
-  MergeRobotextMessageItemResult,
-  ShowInMessagePreviewParams,
+import {
+  type MessageSpec,
+  type RobotextParams,
+  type MergeRobotextMessageItemResult,
+  type ShowInMessagePreviewParams,
+  messageNotifyTypes,
 } from './message-spec.js';
 import { joinResult } from './utils.js';
 import type { RobotextChatMessageInfoItem } from '../../selectors/chat-selectors.js';
@@ -24,6 +25,7 @@
 import type { ThreadInfo } from '../../types/minimally-encoded-thread-permissions-types.js';
 import type { NotifTexts } from '../../types/notif-types.js';
 import { threadTypeIsThick } from '../../types/thread-types-enum.js';
+import { threadIDIsThick } from '../../types/thread-types.js';
 import type { RelativeUserInfo } from '../../types/user-types.js';
 import {
   type EntityText,
@@ -182,4 +184,9 @@
     messageInfo: LeaveThreadMessageInfo | RawLeaveThreadMessageInfo,
     params: ShowInMessagePreviewParams,
   ) => (threadTypeIsThick(params.threadInfo.type) ? messageInfo.time : null),
+
+  getMessageNotifyType: async (rawMessageInfo: RawLeaveThreadMessageInfo) =>
+    threadIDIsThick(rawMessageInfo.threadID)
+      ? messageNotifyTypes.SET_UNREAD
+      : messageNotifyTypes.NONE,
 });
diff --git a/lib/shared/messages/remove-members-message-spec.js b/lib/shared/messages/remove-members-message-spec.js
--- a/lib/shared/messages/remove-members-message-spec.js
+++ b/lib/shared/messages/remove-members-message-spec.js
@@ -2,12 +2,13 @@
 
 import invariant from 'invariant';
 
-import type {
-  CreateMessageInfoParams,
-  MessageSpec,
-  NotificationTextsParams,
-  MergeRobotextMessageItemResult,
-  ShowInMessagePreviewParams,
+import {
+  type CreateMessageInfoParams,
+  type MessageSpec,
+  type NotificationTextsParams,
+  type MergeRobotextMessageItemResult,
+  type ShowInMessagePreviewParams,
+  messageNotifyTypes,
 } from './message-spec.js';
 import { joinResult } from './utils.js';
 import type { RobotextChatMessageInfoItem } from '../../selectors/chat-selectors.js';
@@ -25,6 +26,7 @@
 import type { ThreadInfo } from '../../types/minimally-encoded-thread-permissions-types.js';
 import type { NotifTexts } from '../../types/notif-types.js';
 import { threadTypeIsThick } from '../../types/thread-types-enum.js';
+import { threadIDIsThick } from '../../types/thread-types.js';
 import type { RelativeUserInfo } from '../../types/user-types.js';
 import {
   type EntityText,
@@ -242,5 +244,12 @@
       messageInfo: RemoveMembersMessageInfo | RawRemoveMembersMessageInfo,
       params: ShowInMessagePreviewParams,
     ) => (threadTypeIsThick(params.threadInfo.type) ? messageInfo.time : null),
+
+    getMessageNotifyType: async (
+      rawMessageInfo: RawRemoveMembersMessageInfo,
+    ) =>
+      threadIDIsThick(rawMessageInfo.threadID)
+        ? messageNotifyTypes.SET_UNREAD
+        : messageNotifyTypes.NONE,
   },
 );