I really hope they don't play a bunch of hits. For me that kills the immersion in most parks I'm in, and for one as highly theme'd as this that'd be sad to see. Probably my least favorite part of SeaWorld is that they play so much of it. If they really want it to be their Third Gate, I doubt they would though.
If they want more high energy music, take a look at Animal Kingdom which has music authentic to the area it's based in and it helps keep the theme going without sacrificing anything. They could do something more Polynesian theme'd.