It was so important the security services didn't even bother to warn him when they found out about the affair. You can say 'suspected' spy about anyone. Classic spin language.
The question you have to be asking is why was the memo leaked now and what political game are they playing.
In terms of ousting him - I know nothing about him as a person - but he has lead Nvidia for 30 years during which time it has wildy succeed in not an easy market - whatever this is about, it's not about competence.
Dude, are you kidding me? You have such a corrupt government for the last two years that they openly did insider trading and all the other stuff. I'm sure somebody was in the known and I'm sure somebody did investigation, there was also an article how a higher ups in the government leaked to Nvidia that there was some investigations and internally there was pressure to do nothing about it.