DS can reject your app any time. Since it is busiest time for DS what they try to do is to notify everyone who interviewed by Dec 1 about their status- accept, waitlist, reject. Some schools are really good with it and let you know Dec 1 either way. Some schools will only let acceptances to be known Dec 1 and will drag waitlist till Feb and rejects all the way into spring. You can check past predent records for which school does which...