I understand that for AppDelegate’s continueUserActivity API, we need to return YES if it’s handled by app, and no otherwise, as discussed on the official API doc. However, I don’t observe any behavioral difference between returning YES/NO.

For new apps that adopts SceneDelegate, the corresponding method doesn’t return a boolean. So for apps that uses the scene delegate method, they don’t even need to return this flag.

If iOS actually use this flag in the first place, why does it require it only in AppDelegate methods but not scene delegate methods?

Note: similar pair in openURL where the AppDelegate version returns a boolean but SceneDelegate version does not.