This is essentially the opposite of everything he's said about why he's looking to buy Twitter. It's all about him complaining that the "trolls and extremists" are being unfairly censored. He's all but said he wants to reverse Trump's ban.

There's no world in which Musk is going to be anti-trolling. The dude literally started this whole thing BY TROLLING.

"Trolls" is probably too broad a term since it covers "far-right trolls" as well as shitposters/clowners. Musk is against the former, not the latter. In any case, I'm excited about the potential to shake up moderation; my politics aren't "unfairly censored" by any means, but I'm having the most extreme, caustic positions shoved in my face all the time by an algorithm that optimizes for en(r|g)agement.

Are you sure Musk is against the former? I don't have strong knowledge either way, but it's pretty hard to split that line. The recent history of at least the US far-right can be described as recruiting/evangelizing primarily via "clowning" and "shitposting" that seemed fun until it wasn't. Musk has been fairly open history about palling around with folks I'd easily describe as "far-right trolls", or at least only a few degrees away from them.

I'm mostly unsure if I trust Musk, someone I associate with unfiltered mental garbage intended to en(r|g)age on Twitter to lead the vanguard to moderate out any of that.

I can never know anyone’s intentions, but I also don’t assume the worst for no reason at all. Musk hasn’t measurably changed in the last five or so years, but left-wing opinion of him has nearly reversed. I also reject the characterization of recent right-wing history; I think it is harmless as harmless as any clowning, but the left let that genie out of the bottle a decade and a half ago.