They clearly haven't recognised that it's a forum thread (I wouldn't have, I'd never heard of Piefed before so I'd have assumed those accounts were just a couple of individual people) so your post is useful.
I'm just wanting to clarify - are you then saying that it wouldn't be sufficient for them to remove the @ x @ piefed part and even if they did so, their reply would still appear to that community?
Rimu (npub1vwf…95aa)