It looks like Microsoft's ambitions to completely cannibalize OpenAI is coming to pass. Apparently, Microsoft already has a perpetual license to all of OpenAI's IP (link), and owned all the physical hardware running the OpenAI GPTs. So now that they're about to acquire basically OpenAI's entire staff OpenAI literally has nothing.
I think the interesting angle is the anti-trust angle. The board's ouster of Altman has essentially allowed Microsoft to strip OpenAI for parts without having to compensate the other investors or receive anti-trust scrutiny. It is a massive win for MS.
Also changing jobs is usually a good idea in tech anyways. If they were bluntly offered so many positions like that, they probably got a little bit of a raise as motivation.