From the board's perspective, destroying OpenAI might be the best possible outcome right now. If OpenAI can no longer fulfill its mission of doing AI work for the public good, it's better to stop pretending and let it all crumble.
On the other hand, if it's really just about a power struggle, why not use Altman's dealings with Saudi Arabia as the fake reason? Why come up with some weak HR excuses?
So they're essentially hoping that nobody will sue them but if they are sued that their own words can't be used as evidence against them. That's why lawyers usually tell you to shut up, because even if the court of public opinion needs to be pacified somehow the price of that may well be that you end up losing in that other court, and that's the one that matters.