This does not say anything about what could be done with the land not being touched. If there are going to be other buildings, the removal of impervious surface would be included with their respective proposals. It is much easier to get approval if you are removing impervious surfaces, or if it would remain relatively the same. So for example if they remove extra impervious surface and try to add a building in later on, it would be adding to the impervious surface at that point.
That is also not to say that other uses than parking could already be included in the proposed footprint. For example using a small corner of the bottom floor for offices, costuming, etc. I am not saying definitely yes, but with the information available I would not say for sure no.
But I do not know how tall this thing is going to be. If they are only adding 1 level it may only be to increase parking capacity, but if it ends up being like 3 or 4 stories tall there is defiantly going to be some space freed up. With the space issues they have, I just find it logical for this to be just part of a larger plan to better organize the backstage facilities. And I got to go back to all of the expansion plots currently being used for storage. We know the storage at JP and Seuss will be gone soon, and next to MiB should be expanded not that far out either.