I don't know about that, but I have stayed at the grand a few times and I just call guest services and ask all my questions. They are always happy to help even if you think it's a stupid question, they are happy to help.
I remember they did put a note in the system that I request a king bed the last time I went. We have two little ones and they don't sleep in a BIG bed yet so we put one on the couch and the other in the pack and play.
Just call and ask, all they can say is ... no.
Best of luck!!!!