I would love to hear more than rumor about it, but what I've heard suggested a lot of "tyranny of structurelessness" [1] problems. If the former power structures go away, then people fall back on informal tools, including charm, popularity, favor-trading, and abusive behavior, and a de facto power structure emerges. Since this doesn't really include mechanisms for accountability, it can devolve into lord-of-the-flies scenarios.
The most recent report about this is https://www.pcgamer.com/ex-valve-employee-describes-ruthless... - this is maybe only one step above rumor, but most of what I've heard through the grapevine matches this. Basically super cliquey and horrible unless you are one of the cool kids.
[1] https://en.wikipedia.org/wiki/The_Tyranny_of_Structurelessne... and https://www.jofreeman.com/joreen/tyranny.htm