Probably the Microsoft thing and the direction Sam Altman is taking OpenAI. I imagine that caused a significant shift in workload and nature of work for the people in OpenAI.
>>justan+(OP)
I don't see how it could be something like this. If Sam wanted to do this he wouldn't need to lie. I suspect Sam did something stupid and the board had no choice. I would be very surprised if they actually wanted to fire Sam.