It is breach of contract if it violated his employment contract, but I don't have a copy of his contract. It is wrongful termination if it was for an illegal reason, but there doesn't seem to be any suggestion of that.
> same for MS
I doubt very much that the contract with Microsoft limits OpenAI's right to manage their own personnel, so probably not.
Wrongful termination only applies when someone is fired for illegal reasons, like racial discrimination, or retaliation, for example.
I mean I’m sure they can all sue each other for all kinds of reasons, but firing someone without a good reason isn’t really one of them.
He would also have very good grounds for a civil suit for disparagement. Or at least he would have if Microsoft didn't immediately step up and offer him the world.