I'm guessing USO sees a gain of at least a million (maybe 1.5) but IOA stays relatively flat, maybe a few hundred thousand.
Universal has the same problem as Disney, getting all of the IOA people to also go to USO, getting another million to USO would be a massive success. I'm sure Disney is hoping for the same with Pandora at AK, I doubt it will make much of a difference on the MK numbers but if it has a huge impact on AK's numbers it's a success.
As someone mentioned earlier successful expansions are good for all of us, the success of DCA and HP only encourage Disney and Universal to spend more money and the more they spend the more we (visitors) win!