This is 100% a problem. The whole moderation model for Reddit/Lemmy really invites this kind of censorship, whether intended or not (for example, prioritizing "civility" means that groups of users can start long, infuriatingly bad-faith arguments with anyone who expresses certain views, which will inevitably get them banned eventually when on one random day they manage to lose their temper about it). And even well intentioned things like banning "misinformation" can also feed into this silo-creating effect, yes.
For what it's worth, !politics@piefed.social does not delete comments based on viewpoint or civility, for exactly this reason. There is also !deleted@quokk.au; it was intended as a space to restart conversations or repost things that were getting deleted elsewhere. It pretty quickly evolved into my personal sandbox for griping about the moderation but it could in theory still be that other thing too lol.