Sure, but do you think they'd print it in a memo? They might very well have that policy, but if I was them I wouldn't announce it. It would be a great way to weed out political enemies: Just send out a memo that people must not use "let's go Brandon" but without the disclaimer, right-thinking people will break it just to show a figurative middle finger, thinking there's no way they can be sacked for something this dumb, and then they find out there's nobody on their side. Boom, another position to fill with a cult member.