According to the latest developments, "nearly 500 employees of OpenAI have signed a letter saying they may quit and join Sam Altman unless the startup's board resigns and reappoints the ousted CEO". That seems like it's probably higher than your 20% estimate.
https://www.wired.com/story/openai-staff-walk-protest-sam-al...
Maybe some will come out of loyalty. But then again, when you look at the choice of becoming a MS employee vs. being poached by FAIR, Google Brain or Deepmind, it's no guarantee all 500 will come over to follow the sales guys.
Many of them game from Google. Furthermore, if the choice is "create AI that no one ever uses" vs "create AI that people use" then it's a no-brainer to go with Microsoft. Compute + products + research freedom.
