I have to admit that I only paid passing attention to Campbell's meltdown, but I thought the trans thing was a joke/troll.
Maybe that's just wishful thinking, but I recall when he was just venting about stuff he was complaining in general about how polarized and crazy the internet had become. Paraphrasing, but he said something like,
"It like whenever I meet someone on the Right they're unironically advocating fascism. And when I meet someone on the Left they're so obsessed with correct behavior that saying something innocuous like, 'Come on, boys and girls!' gets you attacked as a transphobe."
From what I recall it was right after saying that that he started saying that he was coming out as transgender. So I thought it was just sarcastic bait to see how people would respond.
But then that was the problem with Campbell, he had genuine serious beliefs, he had a history of Andy Kauffman-like trolling, and he had major mental illness. We will likely never be able to suss out which statement came from what source.