Reddit used to hand out shadowbans a lot for basically every infraction. At one point a few years ago they put out a statement saying that admins would generally no longer hand out shadowbans for things other than spam (which was the intended purpose of a shadowban, to avoid alerting spammers that their spambots were banned)

This is completely different from the "unofficial" shadowban that subreddit moderators can do with automod, where they simply have every comment by a user held in the spam filter indefinitely.