Reddit is fun now; start Tor, try to visit a soon-to-be-banned sub-reddit, enjoy Tor's tracking notifications not present on normal reddit sub-reddits. Looks like reddit is turning into one large honeypot.
I think bitL is saying that reddit embeds some sort of tracking script in “soon-to-be-banned subreddits” that they don’t embed in normal subteddits, and that you can tell this from notifications within Tor
Don't ask me, it's just an observation. I don't think Reddit employs imbeciles so the usual "oops, a bug there!" is unlikely. But given it's pretty easy to track a visitor across multiple social networks in real time, including their real identity, it's good to be aware of it and even being a bit paranoid about one's privacy while on Reddit.
I'd noticed it first when they put r/watchpeopledie under a review, then later banned it. I have no crystal ball to know what are they going to ban next, but I am sure you can find some subreddits that are now quarantined.
Soon one won't be able to train NLP models on certain archetypes of speech if they continue banning everything deviating from preferred topics of their advertising/corporate sponsors :-(