Rovert,
It isn't an absolute gurantee that you will receive word precisely on that date, although if you have interviewed fairly early in the cycle, then it almost IS a gurantee.
Keep in mind that schools can still send you a notification that you've been waitlisted, although if you are going to be accepted then most schools will notify you on Dec. 2 (or throughout that week) of that action.
That is one of the benefits of interviewing early. By now, schools have been interviewing for 2-3 (or 4!) months, and they've had plenty of time to judge the applicant pool for the year -- most schools will make an action on your file (postivite or negative), whether than waitlisting you!