If you actually succeed in getting your waitlist, it will most likely not be for a room currently being shown as available for a cash reservation through Disney in general, but instead one that arises in the future as a result of a cancellation of a reservation made by a
DVC member. The availalble for-cash reservations are not ones considered to be part of the DVC inventory for use by DVC members, but instead ones that are to be used for cash reservations through Disney in general.
DVD owns at least 2% of any resort that it can offer for cash reservations, and the percentage is generally larger, including because it acquires many points through the right of first refusal of member sales and via foreclosures, and DVCM gets many points it can use for such cash reservations through Disney in general via trade-outs by members to Disney resorts other than DVC. In other words, what you are seeing as available through Disney's central reservation system is not inventory available to DVC members to reserve using their points.
As to your chances for a waitlist otherwise, it is probably fairly low, particularly because the first two weeks of December and Christmas week are the three highest DVC demand weeks of the year at WDW, and the third week of Dec is not very far behind. The fact that you are seeking only one night likely means your chances are somewhat better.