I think it sort of goes both ways: Yeah, lockdown has limited a lot of YouTuber's content range, so they put out content that feels quite odd, maybe a bit uninspired, maybe a bit childish sometimes (though I do like Grace's videos personally, they distract me from... well, lockdown).
But with everyone's interaction having been so limited this past year, I would venture a guess that the reason gossip threads for fairly unproblematic creators are taking off is also because we're all bored, have more time to pick things apart, and less time and occasion to engage in "normal" gossip - to complain to friends, share funny anecdotes, and talk to people enough to actually get into disagreements with them.