Hello, in answer to you wanting to know more about the chappelle/mulaney issue and the relation to JM's addiction:
I'll try not to be too long (I failed) because I think it's ridiculous how much overreaction and lack of nuance/grace there is around JM. I'll tackle the whole timeline from before the intervention and also regarding the divorce and kid(s), because I think people wouldn't have been half as crazy if that hadn't also happened and it needs to be addressed.
So leading up to December 2020: AMT removed the mulaney name and his pics from her social media months before. His interviews started hinting that he was living on his own, and that he wasn't doing well (he started talking of death and his own funeral). It'll come out that both he and she were dealing with their own mental struggles. December 2020, she was not at his intervention. He stays in rehab for two months, so until mid-late February. He went to live in jimmy Kimmel's guest house. Olivia munn, who'd openly shown interest for him for years, happens to be near for work. they hook up, make a baby that is born late November. the divorce happens, and AMT seems surprised ("heartbroken"), she most likely thought it'd take longer or that he'd go back to her. JM and OM aren't dating, but decide to coparent: John was happy about the baby and absolutely wanted to be involved. they start dating a few months later. the official public news come quickly, and seem rushed, when in truth all these things hint at years of difficulties.
Bottom line: JM had been in and out of rehab and was freshly recovering when DC happened.
On the kid(s) and JM's and OM's relationship: people conveniently forget that JM said "I don't know NEVER, people CHANGE" regarding having children. When faced with an unplanned baby, he was happy and wanted to coparent. He later dated and married the baby's mother and they had another planned kid. Between the two kids OM battled breast cancer, had an hysterectomy and thus they got help from a surrogate, so yeah the second baby was very much planned and he very much likes having and caring for his kids. Meanwhile AMT said she froze her eggs due to society's pressure and wrote in her memoir that she did not want kids.
Bottom line: people freaked out because they forgot someone can change their mind about kids after getting sober and separated and stepping up when the baby comes anyway, they ignore all of the opinions of the ex they want to champion, and JM was touring with his kid and facing intense backlash because of this when DC happened.
Finally, on to the Dave Chappelle incident: freshly recovering addict, going through a divorce, new dad, on the road, putting together a new hour of material. He already had not one but two openers. The thing is that often, comedians drop in and add themselves as openers. I don't know how much agency the actual headliner has over this, if the venue has more say, if in the case they're both contracted with a same agency matters (like netflix). But considering the historical delicate moment for JM, and the fact DC is considered one of the best comedians, it must've been a tricky situation IF JM was even aware of the drama around DC. There is also to consider that the problematic jokes were, according to accounts from people in the audience, only a few of the entire set, and met with awkwardness. People cheered at the end for the other normal jokes. In those days DC had also been physically attacked (unrelated to transphobia), and JM offered sympathy for that. If he'd turned DC away, he probably would have suffered repercussions in the industry especially while being shaky after rehab. He's well respected by peers, but DC is still more famous and with more decades of brilliant work and they share a big network. JM couldn't afford the consequences of snubbing DC back then and not even now, actually.
All in all, 1: he didn't invite him, 2: he couldn't turn him away, 3: it's not his fault he couldn't "warn" the audience and he had no control over what DC would say.
JM has never ever talked badly about the queer community. On the contrary, he has openly expressed support through his jokes (concrete example: joined jokes in defense of trans kids with Nick Kroll at 2017 independent spirit awards monologue), and worked alongside queer creatives (concrete example: had Mae Martin on Everybody's in LA), openly stated he disapproves of punching down on people already suffering (can't find the interview sorry) and overall never made a fuss about the queer community or cancel culture. The only actual mention of "canceling" was in Baby J, regarding his addiction, and in the context that he can and has done way worse to himself: "What, you want to cancel JM? I'll KILL him. I almost did."
He did not "betray the queer fans that made him famous": for starters, he got famous because he's got the chops and the talent and did the open mic work and has a very particular and effective approach to comedy, I'm begging people to stop saying that because it's ridiculous and gets you made fun of. Since rehab and DC he's got even more famous. Got a few Emmys, hosted the Governor Awards, presented at the Oscars, turned down hosting them this year because he's too busy, Netflix gave him several blank checks. SNL has been celebrating the 50th season, and JM not only has hosted for the sixth time, but was part of the Feb 16th anniversary special during the opening monologue with Steve Martin and Martin Short, and managed to be given ten minutes to do one of his recurring musical sketches. He dressed Adam Driver as a hot dog and y'all are missing out.
In conclusion: JM is not who you should be mad about. He's not DC that has some weird senile feud with trans people even his fans are sick of, and he's certainly no JKR. JM has spoken and acted in support of the queer community more than once, yet it seems this one involuntary incident holds more weight in the indignation machine of the internet.
My sources: their social media, their subreddits where different people's accounts coincide/are very similar, talk show and written interviews (most notably this one, sorry it's behind paywall, I'd read it as my one free article of the month), AMT's memoir, JM's specials with a grain of salt.
It's a pity that Tumblr still freaks out about JM. Everybody's in LA is exactly the kind of whacky surreal entertainment it would love and Baby J is extremely quotable. You should all go watch the Hot Ones interview too.
This is... a lot of commentary when I only really wanted to know about the timeline.
Like. I get it, I am also like this about blorbos, I will admit I would have likely done something similar if someone asked a question about like... Satine from Star Wars? but I actually did not want to learn more about the divorce or Munn or the kids. I very much didn't want to know about all that.
Some of the other context for the Dave Chappelle question, sure, I get why the 'Mulaney was already on thin ice, Chappelle may have just shown up without warning, rejecting him may not have been an option' is relevant, but like... this is a dissertation on tumblr's hate for Mulaney.