Correct, I called as well: Someone said that they'd prefer if we wait until we get invited to fill it out. It may confuse things otherwise. She did say to make sure to send in all the letters of rec, though. (I Bleed Blue and Gold, if you sent it in already without being invited to do so, I would consider calling and asking them how to proceed, saying that you thought everyone was invited, etc. As grasshopper said, they are indeed really nice and I think they would appreciate it.)