I find a bit odd that MS didn't have a couple of people in the board of directors, who I assume accepted Sam Altman resignation (and signed the severance package).
Edit: I just read he was fired, but the point remains.
Per my understanding, the board oversees the non-profit which owns the for-profit entity which Microsoft invested in. It's not clear to me how the non-profit board was picked but equity holders in the for-profit don't have a say on the matter.