In this case it sounds like it wouldn’t be censorship because it’s individual users that choose that particular moderation layer to, for instance, de prioritize certain voices. For others these voices are still loud. Just not for those that turn on that particular moderation layer. That’s how I understand it.
Just being louder than someone else is a kind of censorship. Problem is you can't listen to all 8 billion people effectively, and that's before half of them bring bots
It's not censorship if it's controlled by personal preference. If I ignore a certain subreddit and subsequently don't see it on /r/popular anymore, that isn't censorship. Isn't this here the same?
2. Isn't this still effectively censorship?