Unfortunately it is not - the TDO bean counters might green light another when BoG is fully depreciated say about 2020 or so using a 7 year depreciation schedule.I too think it is the theming. It's a very elaborate restaurant, much moreso than the others in MK. And it's a way to get fairy tale castle/princess type dining without the $$$$ of Cinderella's Royal Table. On top of that, the food is actually pretty good there (I had the pot roast for lunch and loved it) and the prices aren't bad (relative to Disney, of course).
I hope that the restaurant's success encourages the powers that be to put more restaurants in MK with a detailed theme like that. Given the profit potential, I would think this is one type of addition that the bean counters would actually approve.