Not really: we see on Reddit all the time how subreddits quickly descend into herds that can only upvote accepted ideas and instantly downvote to oblivion or ban anything even neutral (much less antagonistic to the subreddit’s worldview).

Anybody who comes by with a different take immediately loses interest in the group and so there’s a self-perpetuating system that makes the group more and more fanatical about right-think and wrong-think.

On Twitter, deleting tweets for wrong-think has largely the same chilling effect and self-perpetuating descent into an echo chamber.

"deleting tweets for wrong-think"

When did this happen? Are you referring to tweets that promote anti-semetism like Ye's? Or to tweets advocating for political violence, like Trump's?

See: Basically everyone who was suggesting the Wuhan virology lab was a plausible source for a virus originating in Wuhan.