Ilia Sutskever never returned to OpenAI after Sam Altman's reinstallation, and Mira Murati left shortly thereafter.

“This claim is partially accurate. Ilia Sutskever, a co-founder and former chief scientist at OpenAI, did indeed leave the company. After Sam Altman's return in November 2023, Sutskever was removed from the board and his role became unclear. He officially announced his departure in May 2024 to start a new company, Safe Superintelligence Inc., which he co-founded in June 2024. However, Mira Murati, who served as interim CEO, did not leave shortly after. She returned to her role as CTO and only announced her departure much later, in September 2024, to pursue her own ventures. Context: The claim conflates the timelines of two separate high-profile departures from OpenAI that occurred months apart following the November 2023 leadership crisis. While both individuals eventually left, Murati remained in her CTO role for about ten months after Altman's return.”