Sorry JT, but you have a terrible track record. You spoke about a "great vision" Disney had for PI, and two years later, it's still empty. You lose. There will be no parking garage. more land will be cleared before that happens, if, and when they deem it necessary.
Second of all, you are making a HUGE assumption that in the next two years, PI turns out to be this amazing, crowd getting, place. What we have seen, lately, is that new additions to DTD typically canabalize other establishments there - they dont bring in additional people, therefore there will be no need for increased parking. Again, there's 100's (if not, close to a 1000) parking spots near the HOB that go unutilized daily. Those need to be touched first before a parking garage is relevant.