It also had a Donkey Kong play area, a Kirby Play area, a Zelda play area and attraction, a Pokemon Training Academy, and a three-story, multi-ride system show building. All fitting within the KidZone plot.
I doubt many of those plans were ever really in consideration, but instead made simply to show Nintendo the breadth of properties and concepts Universal could tackle.
EDIT: When I say consideration, I mean planned to be built rather than just concepted.