I think it's been this way for a while, maybe 8 years. I also think there are certain companies that pay reddit for this kind of engagement. It's a completely unfounded conspiracy theory of mine own, but I think Disney and Marvel fandoms have been synthetically built up using this kind of astroturfed engagement. By using my bots to build a strong baseline, you create the sense that there is far more involvement than there actually is. Because these bots are owned by reddit, they can steer the engagement. It's not a guarantee, but it's a part of an overall strategy.
There is absolutely no question that Disney and Sony are both heavily engaged in viral marketing on Reddit. You can always tell when a new PS5 exclusive is about to drop because subs which almost never hit /r/all end up getting tangentially related gaming memes on the front page with 4000 comme ts talking about how excited everyone is for the new PlayStation game. Same with Marvel movies for a while there. Reddit even had engineers writing code for the Thanos snap thing.
Reddit has very clearly been trying to monetize guerilla marketing for a while, and I think a big part of the API issue is precisely that everyone realized that it's super easy to just cut reddit out of the equation entirely with bots.
Of course the marketing dept of large companies and sports leagues work directly with reddit. They also have the ability to sponsor and boost organic posts, place top comments etc…
I always thought it was so stupid when people complained about "karma farming bots" when it was obviously synthetic content that primarily benefitted Reddit themselves.