I think you'll be led astray thinking this is CEO-specific.

The whole theory of phishing, and especially targeted phishing, is to present a scenario that tricks the user into ignoring the red flags. Usually, this is an urgent call to action that something negative will happen, coupled with a tie-in to something that seems legit. In this case, it was referencing a real post that the company had made.

A parallel example is when parents get phone calls saying "hey it's your kid, I took a surprise trip to a tiny island nation and I've been kidnapped, I need you to wire $1000 immediately or they're going to kill me". That interaction is full of red flags, but the psychological hit is massive and people pay out all the time.