Also, the first level of the structure would need to be high enough to allow the clearance of large vehicles, such as buses and trailers, and those tubes do not look to be the necessary 14 or 15 feet.
But this is all just potential hearsay. I bet they are just conducting a survey for a future structure. This lot, as well as a few others are considered prime locations for future parking structures. This location is expected to carry the extra parking for when Downtown Disney expands into the current Downtown Disney surface parking area.