Over-Under is basically a bet, above or below the possibility.
1.) Over. Logistically, having atleast one or maybe two water-based attractions spread out may be the best option. One of the weaknesses of IOA was that the water attractions were stacked before Kong came in, and while it's still there, it isn't as bad as before.
I would assume two would happen, but the question I would ask is what would they do.
2: I need more information. Are you asking if they are doing another waterpark?