Affairs are commonplace. Most likely the internal findings from the investigation point to something more troubling/illegal

The board probably determined it would impact the stock too negatively to keep him on.

After the news about a potential foreign compromise, disclosure of an affair with a subordinate is pretty damning. One can be discounted as poor judgement. Two is a pattern that's hard to dismiss. I wonder if we'll learn of other shenanigans or whether kicking him out stops future (possible) disclosures.

>> he made Nvidia (and investors) so much money.

Right now, he made them lose 700 Billion dollars. So the investors lawsuit also will be the biggest in history.