I cannot think of a single reason why posting an acceptance you're happy about on your FB would be an issue. At all. Please explain. FB is the ultimate tool of narcissism in which you are the star of your own reality show. Why are you even friends with people who wouldn't be glad to share in your happiness and accomplishment?
I would say, and I'm sorry to, that in most cases it's a bad sign. Michigan, for example, even invited some waitlisters to their recruitment weekend a few years ago, when admitted students couldn't attend for whatever reason.
I've done this with some success in the past. I corresponded with the graduate adviser of the program and told her I'd been advised that in some circumstances, such-and-such funding (in your case, summer) was available in similar programs and would program A be in a position to offer me some of this kind of funding? I also let her know, vaguely, why I required the funding (so for you, maybe you hope to work on a language or have specific travel or research you could be doing).
I definitely prefer tactful ways of saying it. Rejection is such an ugly word. I prefer "declined." Or "unable to accommodate all the qualified applicants."
I was watching an episode of MTV's Teen Mom 2. One of the girls was fretting about not finishing high school and trying to sign up for beauty school. I was thinking "I may be feeling worthless about not getting any acceptances, but at least I am not a teen mom with no education." And right then, I got some good news!
Um...yes. This. I am positively murderous when my email pings. I've spread the word to various loved ones (the ones I'd prefer not to wish I could punch in the face) that they should not email me for any reason. Sometimes my sadistic phone will ping when I have no email.