I see that some are priority and some are standard. This is my thought on it:
People who ordered right away already have an iPad claimed, it will ship out using standard shipping and arrive on time.
People who ordered later are going to have to wait until another shipment from China hits here and the way it is looking they aren't getting it until last minute, so Apple will have to bump your shipping to priority to meet the deadline.
Sorry but that made me LOL. So this is how people come up with stuff. You pulled that out of the air. Even people that ordered on the first day are seeing their status change to Priority. Your speculation is funny to me. No offense.