Unless plans have changed or I'm missing something, there are three new buildings planned for this project (according to
@BehindThrills on X), with none of those new buildings being planned for the old RRR station.
I know we're expecting coaster track to run through the old RRR station area, but it seems like a missed opportunity if they don't use that space for something more. You could easily fit a half acre building there, or even more if you expand to run across the Despicable Me building and up against the stage for another .15 acres or so (for covered / outdoor entrance and queueing area, for example).
Comparing to USH, Secret Lives of Pets is about the same size (about .5 acres, though the shape of that building is basically a triangle). Even the Despicable Me building is a comparable size, Villain-Con footprint is significantly smaller, Transformers is slightly larger (~.7 acres), most stage shows are around .5 acres, etc. My point is, it seems a decently sized attraction could fit there. If they build something here, the entrance could either be on the side closest to the concert stage (see pic below) or on the right-hand side of the Despicable Me entrance.
The obvious thing holding this back would be that they would need to design the track to run over, around, or through the building. But, they did exactly that with RRR and the current structures.
One potential idea is to build an Orlando version of a Super Silly Fun Land, which could be covered/shaded but not a full building structure,
similar to Beijing. Springfield is potentially closing, so this could be the new home of the spinner flat ride (retheme Kang and Kodos) and carnival games, in addition to a new flat ride (Beijing has a kiddie-coaster, but Orlando could do something else as they have a Trolls based kiddie-coaster). With this concept, they could run the new (F&F?) coaster track straight through this area, as it would add kinetic energy to an already intentionally chaotic kids area.