I think the massive 'green bridge' just means that soommmmething is going there. Universal was able to convince the local government that there would be so many people crossing the street it would create traffic and safety hazards (its already a very congested area, especially with that highschool within a stone's throw). Now we just have to guess what's going in those spaces.
Google maps satellite view will provide a lot of insight on this. Its true, Wet 'n' Wild would fit perfectly into that small plot we're discussing. The plot of land to the right of CBBR also is huge and looks completely prepped for construction; so I'm guessing that's where the 5th hotel will go. But possibly this is the 3rd gate, well 3rd (dry) gate.
Its really surprising seeing the amount of space a waterpark can fit into. It makes the on-site hotels look like a waste of space! The entire wavepool of WNW can fit into the outdoor entry 'hub' of CBBR. That's insane!