You know I actually went and looked at the satellite view and that actually could make a lot of sense. The area adjacent to Kid Zone isn't actually a wing of the hotel but rather parking lot space. There's also a parking lot on the other side of the entrance which if converted to a 3-4 level garage could create equivalent or even increased parking for the hotel, that would then free up a much more sizable piece of land than the ET building.
See below:
Red: Existing Kid Zone
Green: Expansion into hotel area
Blue: Parking Garage