They're allowed to state their opinion if it does not negatively impact the finances of the company. That is the life of a CEO. You get the big money and you get the responsibility of being in charge.
It's only CEOs who go against the left who actually get fired.
This is not a principle that the people who got this CEO actually live by or genuinely believe in. It's a post-hoc excuse for collecting a scalp from the other side. Let's speak plainly about what's really going on here.