It's always best to phrase your request in terms of describing what features you're looking for in a room, instead of naming specific room numbers. Especially at DVC resorts, which tend to run at high occupancy, so there's less chance that a specific room will be available.
I know some people tend to see giving certain room numbers as helping the room assigner, but it's really the opposite. If the rooms you request aren't available, then they have no idea why you wanted them, so no idea of how to fulfill your request.