That’s not a thing for the entire site, so you must be confusing a ban from a subreddit with a sitewide ban, and subreddit mods are (for some reason) allowed to do whatever toxic, evil thing they want, including banning people for subscribing to another subreddit.

How would that even work? Moderators don't have access to any lists of users that have subscribed to their subreddits.

Don't forget that this is a company where the CEO can apparently go in and edit other user's posts for revenge and he was put in place and tolerated because he was somehow better than the person in charge before him.

Just posting in the "wrong" sub can get you banned all across the platform (no matter what you actually said).

Of course, this violates several of the Reddit mod TOS/guidelines, but Reddit doesn't care.

Yesterday, one of the top stories in the default /r/news is the attempted assassination of a Mayoral candidate.

Today, it turns out that the guy was a far-left BLM supporter and all mentions and threads have been retroactively scrubbed from the sub.

It's just a large echo-chamber supported from the top down. Would it be exceptional to think that this information could "leak" into the hands of the echo-chamber mods?

Worse than an echo chamber, it's an intentionally curated propaganda site. At least in an echo chamber you could scroll down to see the unpopular posts.