It would appear it's mostly bots, probably paid for by reddit (or interested groups) to muddle the waters.
I have seen countless posts trying to discredit the fediverse, how it won't work because it isn't financially backed (completely ignoring that email is still a thing), or how Mastodon apparently failed. On top of that, there are tons of comments in the threads for subs that went dark where the commenter argues "all this does is hurt the sub". but when you look into the commenter, they have no previous history of being active in these subs at all.
But, i've seen this kind of activity all over reddit for the past 2 years. Especially when something unpopular is happening. There is a lot of the same type of crap you see during the presidential elections of the US. A lot of fake comments, posts, and statistics, and other things to try steer the public opinion in an engineered direction.
the people still on reddit after the 30th when the third party apps close down, i personally believe can stay there indefinitely. these people, and i, do not exist on the same wavelength.