I don't think she actually had anything to do with the coup, she was only slightly less blindsided than everyone else.
So her move wasn't stupid at all. She obviously knew people working there respected the leadership of the company.
If 550 people leave OpenAI you might as well just shut it down and sell the IP to Microsoft.
Actually for MS this might be much better cause they would get direct control over them without the hassle of talking to some "board" that is not aligned with their interests.