I see a bunch of "why did people who knew something not say something already" and I have some personal insight into it because I've been in the same situation. I'll try to break it down a bit:
if you've ever been involved in a social group that involves a few hundred people, for long enough, you'll eventually hear rumors of certain people being ones to be cautious of.
Usually this information won't be directly actionable, lacking indisputable evidence, and you end up only being able to bank this info in your head as reason to be cautious of getting directly involved with that person on a business or creative level. You'll see other people you know working with them, and think to yourself "do they know?" but you don't necessarily have permission to share what you know, or what you know is so vague, you can't act on it. You can only tell people you're really close with on a genuine friendship level, not the couple hundred acquaintances you have in common.
And when people do raise those concerns in public, they get enormous "always been cool to me!" pushback, and they get retaliation in all kinds of tiny or major ways, especially if the person in question is deeply entrenched, is useful to know, has real power in some way over resources like media coverage or job hires or galleries or venues...
but then, maybe years later, if the behavior you've heard about is a pattern and not a one off miscommunication, it'll blow up in the light of day and people will finally talk about it and say vague things about knowing that person was sketchy, or they had heard this or that. And that which ever incident is the one that hits the light of day is part of a pattern, not an isolated incident. That's why people are taking what's happened so far very seriously.
This happens in music, in comics, in venture capital, all kinds of circles that are large enough to have multiple social circles people interact with.
