This post follows up the Analysis of the Facebook.app for iOS [v. 87.0].
The version 88.0 of the Facebook.app has now been released:
As you can see from the smaller download size, the duplicated resources have been removed. This is confirmed by looking at the app content using GrandPerspective:
Only some really small resources escaped the cleanup. The ‘FBFacecastTipJarResources’ resources are indeed still duplicated. Example: