In case OP shows up, we believe you and support you! Speaking out like this is hard but it's the best way to help the community you love.
Not that I think he's lying, but... why?
I don't know who any of these people are but I don't like the idea of hearing one person's account and automatically assuming it's true. At least not in the case of assertions that are potentially career-ruining.
That's the key point right there. The target audience is the Racket community, who do know who these people are. No one is out to ruin Felleisen's career, he will be fine no matter what. But the Racket community has an interest in his effect on that community. We are much worse off without Butterick's involvement.
I mean, why do you assume that? I don't know the Racket community, but if he is "the self-styled leader of the Racket project" being potentially forced to step down/ousted seems like it would very much impact him personally.
Felleisen is very secure in an academic career and his status on the Rackt development team does not affect his position or his paycheck in the slightest. You can google him and look up his wikipedia entry.
And yes, he won't lose his job or end up destitute, but I find the insinuation that this means "he will be fine no matter" quite strange. If it prevents him from continuing his current research work (I don't know whether that's the case), I'd very much count that as impacting him personally.
So zero knowledge then.
I don't think anybody want this to be career ruining. It is really hard to check assholes with authority. The least we can do is take this person's complaint seriously.