Respectfully, I do not believe that any resort has been completely sold out at the 11 month mark,
except perhaps NYE night.
Sometimes the newer members misunderstand the booking rules. They think they can't book until their use year starts and the points are in their account. But that's not correct. This turns out to be a big reason for some of their frustrations. Once they understand, the "probelm" goes away.
Whenever I have heard complaints about the BWV selling out at the 11 month window, it turns out that the member wanted a standard view or a Boardwalk view unit and was not willing to book a Garden/Pool unit. It's not correct to say the resort was sold out in those cases - a limited type of room may sell out quickly, but a BWV owner should always be able to book at least a Pool/Garden view unit if he/she calls when the 11 month window first opens.
FWIW, we have owned the BWV since 1999 and stayed there many, many times. I nearly always book at 11 months and I have never encountered a sold out situation - even though we always book the more limited standard view units and stay during the popular early December and Food & Wine time periods.
Perhaps NYE night sells out in one day, but that would be the only time I can ever imagine that the BWV would be sold out at the 11 month window. Otherwise, it just doesn't happen. (It may with the booking change to be from "check in" rather than"check out", but that remains to be seen. The new system hasn't been in effect long enough to see how it will work for the really popular times of the year).
DVC cannot legally "oversell". I do not believe they have. The system is designed to be at or near capacity every night of the year. The reservation system works on a first come, first served basis. There is no guarantee that members will be able to stay when or where they prefer. Members who do not book early may have to stay at the less popular times in the less popular units. The system is designed such that the early bird gets the worm.
If members don't get what they want, it isn't because the resorts are oversold.