> If OpenAI ceased to exist, can Microsoft take the code, model weights, everything of ChatGPT 4, and just continue developing it and produce a new MS-ChatGPT based on it?
Well, if OpenAI magically got erased from existence, probably.
More realistic scenarios, like if they continued to exist, but there was a legal dispute about breach by Microsoft of the agreements by which Microsoft got access to the IP, may be more complicated.