The short answer is NO.
UY has no meaning at all when it comes to making a reservation.
The reason I said no has to do with cancelling a reservation. With a UY shortly before you normally travel, if you cancel a reservation, then you have nearly a year to make a different reservation. Or to bank your points.
If you had a UY of Dec, and made a ressie for Nov, and say cancelled it in Sept, then you would have little time to use those points, and you'd be past your banking windows.
But again, UY has no bearing on making ressies or the 11 month window. All you have to do is have the points available at the time of travel.