They are not restoring them, communities go public again making them appear in your profile. For some reason someone thought it was a good idea to hide them in your profile if the community is not accessible.
I deleted my comments for couple of weeks now, today there were only two left, looks like i’m about to finish.
I know that for sure because i export all my deleted comments and i can’t find the reappeared ones in my backup, so i in fact haven’t deleted them.