The board's major mistake was not communicating why he was let go.
My guess is that the likely reason why employees threatened to go was that they felt Altman had the best chances of making the for-profit arm's shares skyrocket. As a non-profit company's board, I'd be fine letting those people walk out the front door along with the CEO that was just fired.
It is my understanding that the key personnel who developed the actual technology were not part of the group threatening to leave. It was mainly the group in the for-profit arm that Altman had trojan-horsed into the company structure.
> This included the company's key leadership.
I'm not aware of the machine learning researchers responsible for the core technology threatening to leave. Who were they?