Not to beat a dead horse on the Nintendo store....
But if they realistically wanted to build another big restaurant or store, something needs to be replaced. Id imagine Margaritaville is a good $$ maker so I dont see that leaving although the space and location are PRIME. With the Margaritaville resort open I do think this is a possibility in the next few years, depending on the success there.
If not, Red Coconut and Marley's is another potential spot, but really the only space that lets them get creative is the mini golf space. I have no idea if and how much $ Universal makes off that, but thats space that could be used for a multilevel Nintendo store. Hits non resort/north campus guests right as they walk into Citywalk from the parking garage, and hits them on the way out. Also, guarantees resort guests get to the very end of citywalk and see what they have to offer.
Idk, just gimme a damn Nintendo store lol.