They have the GPUs and there's a GPU shortage already. What do you think is going to happen when they lose that access in $10bn compute? Given the shortage and other vendors being mostly locked up already, there's not much OpenAI can do. And that's not considering that the board is facing immense pressure internally starting from the very temporary CEO that they put in place two days ago to various members of senior leadership threatening to resign (with many employees being paid in options dependent on valuations that the board just destroyed). The board may have de jure power but that is nothing without the de facto power associated with it.