The only technically person who matters here, the one who came from deepmind and who is the worlds top AI researcher, is sure as hell not going to follow him since he’s the reason Sam is gone.
Including Ilya Sutskever who is (according to the posted document) among the 550 undersigned to that document.
It's pretty clear this is a fast-moving situation, and we've only been able to speculate about motivations, allegiances, and what's really going on behind the scenes.