Taken in the micro looking only at DVC it might be stretch. The wording the would allow it would be that DVCMC has full and complete power over the reservation system. I could see the argument that it wouldn't be allowed. But then you look outside DVC and at least 3 other systems I'm aware of that are based in FL have either created a VIP system or created a system where some owners are allowed to make reservations before other owners or both. I think we could argue the VIP system but I think it'd be the only way to create a system where there was a difference in reservation windows and to do so would likely require X number of qualified points. Wyndham has a VIP program but I'll let others speak to how it works as I'm not as well versed there. Marriott has 2 systems, the weeks system where those with multiple weeks can reserve a month earlier meeting certain requirements and the points versions where the higher you go VIP the earlier or longer you can reserve. Bluegreen allows VIP members to go on a wait list earlier then they make the reservations before others have access.
