diff --git a/lib/utils/drawer-utils.react.js b/lib/utils/drawer-utils.react.js
--- a/lib/utils/drawer-utils.react.js
+++ b/lib/utils/drawer-utils.react.js
@@ -26,7 +26,7 @@
 
 function createRecursiveDrawerItemsData<LabelStyleType>(
   childThreadInfosMap: {
-    +[id: string]: $ReadOnlyArray<LegacyThreadInfo | ThreadInfo>,
+    +[id: string]: $ReadOnlyArray<ThreadInfo>,
   },
   communities: $ReadOnlyArray<ResolvedThreadInfo>,
   labelStyles: $ReadOnlyArray<LabelStyleType>,
@@ -66,9 +66,9 @@
 }
 
 function threadHasSubchannels(
-  threadInfo: LegacyThreadInfo | ThreadInfo,
+  threadInfo: ThreadInfo,
   childThreadInfosMap: {
-    +[id: string]: $ReadOnlyArray<LegacyThreadInfo | ThreadInfo>,
+    +[id: string]: $ReadOnlyArray<ThreadInfo>,
   },
 ): boolean {
   if (!childThreadInfosMap[threadInfo.id]?.length) {