I think you're underestimating a CEO's ability to smell bullshit. In fact many will have written similar letters themselves. The difference is: a CEO usually wouldn't care about security nor privacy violations like this because it's unlikely to affect the bottom line of the business they're managing.

Thankfully most (in fact all) places I've worked, it's not the CEO who decides which video conferencing (et al) solution people use, he delegates that responsibility to his CTO or equivalent. Who has almost always then delegated that decision to me :)