Applied to the MA in English Lit at the University of Arizona, hadn't heard anything at all, then two days ago I received a fully-funded acceptance into their PhD program! Though they were my top choice when I was applying, Rochester's offer-- for me-- is pretty much unbeatable. So if anyone is still hoping for a spot at U of A, I will be declining!
I wouldn't say obnoxious, but I would say it might be a tad unnecessary. Could you compromise with a letter stating your continued interest? That way you are still in contact with them, and I'd like to imagine it helps put your application in a more favorable light. (Plus it's always fun to close-read their responses )