I think maybe the trigger was that Sam was doing some board-unfriendly moves like signing business contracts with MS without running it by the board, and they found out about this and booted him out hastily. But now they got too much backlash, and are hoping to just go back to normal, but still can't accept Sam keeping the board seats in case he tries again.
Ilya, if he is being rational, needs to choose between an OpenAI that he has some continuing involvement in, lead by Sam’s gang, or bankruptcy.
He is fooling himself if he thinks there is a third path here.