I subbed to r/conservative myself I tend to like to browse most political subreddits left and right. I didn't see any "proving yourself to get a pass to enter" I just remember making a comment on a post about Tiananmen square on the anniversary clicking the join icon then getting 2 automod messages one telling me that I'm banned from justiceserved and another alerting me that I've subbed to r/conservative.as simple as that. I think you might be refering to r/blackpeopletwitter which uh I think this screenshot should speak for itself