Oh, that's the role of Universal Creative then! Just imagine being taken down a stream in a raft through some ancient ruins, then being trapped in a show area with PF-like effects, then being spat out by workers (costumed, of course) into multiple water slides where the story continues. Or maybe tour a mountain's many caverns and have various options of "escaping" like a dark/water ride (AquaTrax system, anyone?) or braving the waterfall on the peak of the mountain, etc. The idea of a water park has so many possibilities that will all work out if executed well, which I'm sure Universal will do with this.
In terms of the name and the theme, I'm sure that the entirety of the project will have its own backstory, perhaps related to IOA (like in my Legendary Seas project), but not anything like "IOA's waterpark!"