Well yes and no. If someone opts not to use their week, they had better be letting Disney know at either the 11 or 7 month windows. Otherwise, they won't have much use for their points, as there won't be anything available for them to use it on. They can't just wait until a few weeks prior. So if they have guaranteed week 50, they would have to decide somewhere between the middle of January, and the middle of April, if they wish to use their points at a different resort, or at a different time. That would still leave plenty of time for someone else to book that unit.