If what he regrets is realizing the divergence between the direction Sam was taking the firm and the safety orientation nominally central to the mission of the OpenAI nonprofit and which is one of Ilya's public core concerns too late, and taking action aimed at stopping it than instead exacerbated the problem by just putting Microsoft in a position to take poach key staff and drive full force in the same direction OpenAI Global LLC had been under Sam but without any control fromm the OpenAI board, well, that's not a regret that makes him more attractive to Microsoft, either based on his likely intentions or his judgement.
And any regret more aligned with Microsoft's interests as far as intentions is probably even a stronger negative signal on judgement.