Messages from the CEO to the whole company should be carefully checked, and in my experience they seem to be. Spelling/grammar is just a tiny part of check, there is also the whole inclusive language/not offensive to anyone set of checks, and the is this even legal check (perhaps more, that is what I can think of offhand).

Messages to a single vice president get much less care.

I agree that's the reality, but that VP will follow your example - as a leader, excellence is a performance, a superficial presentation for others, not something to do in private. Also, it's normal to not take your reportees seriously (to some degree).