A simpler explanation is that SamA is consolidating power at the company and pushing out everyone who hasn't been loyal to him from the start.
And it also explains what Mira (and everyone else who left) saw; the true cost of a failed coup and what Sam Altman is really doing since he is consolidating power at OpenAI (and getting equity)
I feel like either they're not close at all and the people know it's all lies or they're seeing some shady stuff and want nothing to do with it