Not neccessarily, you will go into the National Pool, and will compete for the remaining appointments nationally. A rep with only 1 open slot, could actually end up with several appointments from his/her district, but only one would be officially "charged" to him/her.
If you look at it mathematically, adding up all the MOC available slots, the 100 Presidentials, and the other Nominating categories, there still isn't enough to fill a class, so they go to the National pool, of remaining candidates with noms, and they compete for those extra appointments to fill the class. Its a huge puzzle, and takes time to form the best class possible, which is why notifications take so long.