I would definitely say the board screwed up.
https://www.forbes.com/sites/alexkonrad/2023/11/17/openai-in...
The board has no responsibility to Microsoft whatsoever regarding this. Sam Altman structured it this way himself. Not to say that the board didn't screw up.
Nothing stopping a non-profit from owning all the shares in a for-profit.
[1] https://finance.yahoo.com/news/top-10-holdings-mormon-church...