There are different levels of “public”. Musk doesn’t need to publicly announce he’s telling all the advertisers to fuck off, he could tell it to them on a private call and then the public would most likely only know what advertisers are pulling out. The whole “fuck off” statement never needed to be public, Musk made it public because he can do whatever the fuck he wants. The same goes for a lot of things you see about Twitter. He didn’t need to do his things in public, he simply did.