Your first post made it sound as if a non handi person would be allotted a handicapped acessible room even if a handicapped person came along and needed it. I can tell you that would be illegal. In fact on
DCL, if a party is booked into a handicapped stateroom without disability, and a handicapped person comes along requiring it, they will move the first person out of that reservation and into another stateroom.
Since the DVC resorts use room ready, or assignment shortly before check in date, this usually is not a problem. This is why Special Services has the room allotment of accessible rooms to reserve and assign. If nobody with a handicap is not already booked into one, then they become open season for anyone without handicaps.
This is exactly why handicapped parking spaces cannot be used by non handicapped individuals, even if they are empty.