the entirety of stackoverflow is not enough data to make the AI work properly. They need terabytes of text, stackoverflow has about 50-100GB of useful data at most

There is an implicit threat of government censorship there, even if it is ultimately toothless. And since valve is clearly not the one interested in increasing moderation, your point about the 1st amendment “not applying to private forums” is irrelevant

if it’s the government that is doing the censoring, against the will of both the users and the private company, how does it not apply here then?