So your thought is that DVC is holding back at least one room and releasing it right at 8:00 am? That is very possible because they own points at all the resorts an can very well be booking...and have a way to set a release faster into the system.
As long as what you are seeing is the room going at the 11 month mark, and then coming back after it is passed (+1) day, then it matches how the system should work....
What I can tell you is that today, May 9th was not there prior to 8 am, and when I tried to start my trip for the 10th, I got to the calendar, showed I could book starting the 10th (still no room on the 9th) and by the time I hit continue, I lost it, but the 9th was now there...and it was about 5 seconds beyond the window...it seems like it was the only room too because as soon as I booked, and went back...it was now about 8:01 am, the 9th was now gone again.