A
DVC stay is prepaid in the sense that the points for the entire stay are already charged whether or not you use the room the first night. This is different from booking a hotel stay where you might only be charged for a single night of a no show, with the rest of your rEservation canceled. When we had a weather delay due to snow and missed our first night of a BWV stay, we did call the resort to let them know we would still be arriving and would want to get in the room right away, since we were switching to a very early morning flight the next day. We figured we had paid for the room in any case, even if no one slept there the first night.
We have also paid for (in points) an extra night when we had a very late departing flight so we would have access to the room for all of our last day, rather than having to vacate the room by 11 am. That time, as a courtesy, we did notify the front desk so they could have housekeeping get into the room first thing the next morning, preparing it for the next guests.