As far as I know, Scott Aaronson has been on leave from UT Austin to work on theoretical foundations of AI safety at OpenAI since June 2022: https://scottaaronson.blog/?p=6484
"[Note for people who might be visiting this blog for the first time: I’m a CS professor at UT Austin, on leave for one year to work at OpenAI on the theoretical foundations of AI safety. I accepted OpenAI’s offer in part because I already held the views here, or something close to them; and given that I could see how large language models were poised to change the world for good and ill, I wanted to be part of the effort to help prevent their misuse. No one at OpenAI asked me to write this or saw it beforehand, and I don’t even know to what extent they agree with it.]"