Since there is no guarantee of a free upgrade to a Magic Kingdom view you could still call CRO to see if someone cancels a reservation before you leave. The other thing you can do at check-in if you are not upgraded, is to ask if there are any rooms on the Magic Kingdom side. Incase there is chances are you will have to pay for the upgrade because if they were going to give it to you for free, the Cast Member would tell you right away since a free upgrade automatically comes up when they enter your name into the computer at check-in.
Incase there is chances are you will have to pay for the upgrade because if they were going to give it to you for free, the Cast Member would tell you right away since a free upgrade automatically comes up when they enter your name into the computer at check-in.