Non-competes (with three narrow exceptions, none of which apply here), are void in California (and the practice of making employees sign them even though they are unenforceable, a historically common way of making workers think they have less rights than they do, will become an actionable tort itself, on top of the agreements not being enforceable, due to a law going into effect January 1.)

Obviously, anything that Altman does that would compete with OpenAI will have OpenAI lawyers circling around looking for indicia of use of trade secrets or other IP, but non-competes aren't an issue.

Virtually all non-compete agreements are illegal and void in California. Limited exceptions exist for LPs, etc, but they do not apply here.

Non competes are not enforceable in California

They are based in California, where non-compete agreements are not allowed.

As everyone else has mentioned, there is no such thing in CA, but you can sue if employees reveal company secrets to their new employer. OpenAI would probably have a strong case if they suddenly released a copycat product soon after leaving.

Those are basically unenforceable in California.

People are speculating without knowing the details.