i do belive it will be a flying coaster, I don't think it is going to be 500 feet. I'm also not sure if Kinzel even said that. They make choices based on investment. A flying coaster is an attraction by itself, and would not have to be 500 feet. Remember, most of the GP has never heard of, or seen, a flying coaster.
Now what would be cool is if they did at least one portion over the rapids ride.