It seems like if a staff member changes the ownership of a whisper to a user who cannot use whispers, the user without whispers access can see “their” post, even though they should be unable to.
For example (this user is a TL4 without moderator or admin privileges, and only staff have access to whispers):
That’s an interesting one. How about if you are allowed to make a whisper, create a whisper, and then are removed from whisper allowed groups - can you still see your whispers even then?
I can see some old whisper posts I created in public topics on Meta - not any other whispers though. The logic seems to be that a whisperer can see their own whispers. It feels like a bug.