
MadiHawkins:
To add to the above (not a bug, but maybe sth for considering):
The user's own comments written under his own (once public) custom list which later got deleted cannot be accessed directly, thus cannot be deleted from the comment history.
If I don't wish for a certain custom list to exist anymore, it's rather obvious I don't want these comments either. They are public (visible to everyone) and attached to the "List unavailable".
Thank you for adding your observation.
It doesn't work as it should, so for me, this is essentially a bug.
Going over what I wrote and what you wrote, I'd conclude:
If the "parent post" (in feed, a list, a review) is deleted (or maybe it's not deleted in the database, just hidden), the comments on that parent post are not. But they are also not accessible anymore, not even for the user who made the comment.
(I'm not sure what's going on with the comment section on drama pages, though)
And now that the comment history has been made available, the not-deleted-but-inaccessible comments, which nobody could see before, are visible. That is definitely A Problem.