Ms. Murati wrote a private memo to Mr. Altman raising questions about his management and also shared her concerns with the board. That move helped to propel the board’s decision to force him out.
https://www.nytimes.com/2024/03/07/technology/openai-executi...
It should be no surprise if Sam Altman wants executives who opposed his leadership, like Mira and Ilya, out of the company. When you're firing a high-level executive in a polite way, it's common to let them announce their own departure and frame it the way they want.