If school can arrange the transportation to Disney and go back home by ourselves, I agree this arrangement. On the other hand, I think no place can be held graduation ceremony in Disneyland, but in Disney hotel.
I think it's better to arrange it in the YYC club. It's good for all parties, including the kids, parents and school. We don't have to spend a long time on travelling and it's really hot to go far away at Disney in July.