I'm still of the opinion that you were wrong. You judged him by assuming he was going to make it all about him. Maybe you were right, but maybe he thought it would bring more attention to the cause, make it a bigger event.
He's a drinker. He is also your boss. You putting yourself in the place to manage his behaviour isn't smart.
So while everyone here pats you on the back saying well done you can bathe in the fuzzy feeling of being right. But clearly you don't really believe that or you wouldn't have posted.
I've always been honest with you. Maybe a bit brutal, but rarely have I given you incorrect advice.
Keep on managing his drunken behaviour and see where that gets you