The easiest way to explain this if you have no clue how fediverse works is - imagine there is a third party reddit, discord, X or some other platform’s client that lets you browse their website/content. The developer of that client made a list of users whose comments/posts are hidden in said client. In reality, the client does not have significant user base and this affects almost nothing. Some users might not see your comments, but that’s really their problem more than mine/ours at this point.