Sometimes circumstances change and a school will decline the opportunity; and, with the current financial situation many schools are facing I would not be surprised if some may have taken a pass due to the costs involved.
It is expensive to host such events and the cut of the gate schools receive does not cover all expenses--especially the increase costs of utilities and expenses associated with the wear and tear on buildings--not to mention expense of custodians and workers unless an all volunteer force is organized.
Don't know if this is the situation, but would not be surprised.