The only way you'll ge tupgraded to a different resort is if the one you are booked at is overbooked. And those cases are very few and far between. Even if the CBR was oversold, they would move you to another moderate before sending you to a deluxe. Because each resort operates as an independent cost center, they have to pay the next resort to accomodate you. You would be paying the same amount either way. So they wouldn't want to spend extra money to put you up at a deluxe when they could put you in another moderate and not lose money.
The only times I can remember people being bumped to another resort at check-in was when the Tupperware (?) convention overstayed, and a LOT of people who were booked at the Y/BC got bumped to rooms all over the place. Whadda mess!! Most were accomodated at the BWI, S&D. Some were sent to the GF, Poly and CR. But a very few ended up at moderates, and were rightfully so VERY unhappy. Lots of rooms got comped. That was back in 1997 maybe?
You could request an upgrade to a waterview or something like that when you check in a the CBR, but don't expect an upgrade to another resort, it's simply not going to happen.
Anne