I was just going to look that up so thanks for that. This really can't be more of an overflow lot, even for future developments there.
I think @Disneyhead hit the nail on the head. It will be a car park for the construction workers and I think this is somewhat telling about the speed they're planning to build this.
You'd imagine they would build the car park first and then work from there but it looks like they will be building the car park, theme park, CityWalk 2.0, infrastructure and probably a hotel or two and 2,451 spaces is a lot of workers.