As noted in the release: "The majority of the board is independent, and the independent directors do not hold equity in OpenAI."
He confirmed it verbally as well in his May 2023 hearing in Congress https://twitter.com/thesamparr/status/1658554712151433219?la...
> Even OpenAI’s CEO, Sam Altman, does not hold equity directly. His only interest is indirectly through a Y Combinator investment fund that made a small investment in OpenAI before he was full-time.
That word “directly” seems to be relevant here.