Personally, if MSHI is going to see a MASSIVE overhaul, like how Springfield was for USH and Hogsmeade for both coasts; I can see this.
Items Removed:
Hulk Lockers (Temp Removal)
Fantastic Four Café
Dr Dooms FearFall
First Building on the side of the land facing the lagoon (when you enter from Port)
Additions:
Avengers E-Ticket Dark Ride {1} (Cobalt Blue/Light Blue)
New Superhero store {2} (Yellow)
New lockers for both Avengers and TIH (Separate) {3} (Red/Green)
New Full-service Dining location {4} (Orange)
Wider pathway for the area {5} (Light-Grey)
(Pic down below, with explanation as usual with these things I do..)
Lets go on and say this..
First off, I think "The Avengers" would be a massive 3D Multi-Sensory dark ride experience, using a mix of Practical effects; and screen based movements to give off the sense of flight in a MCU New York. It would also include the version of Avengers Tower; seen from the recent addition to the MCU Avengers series; "Avengers - Age of Ultron" as it would have Ultron as the main antagonist of the attraction.
I also think that the Full dining would be moved to the side facing the lake; more closer to Hulks dive to it, as it would be a Two floor option; similar to USH's Springfield. It makes sense to have a dining option there; and it would add some more people to that right side of the road in MSHI. And also, a new gift shop for Avengers; as it would make sense.
I also putted in two new locker locations; each for their separate ride, as I think Avengers would be bringing back Kuka to do a Second-Gen version of the bench technology from FJ, but that's just me. And, I think that during all of the work; the buildings around MSHI would be getting new paint and theming to accommodate the new style of theming that'd be introduced to the island, so it matches with TIH and the new E-Ticket. And, that I also see a change to Spideys façade; but in a way, being more of an improvement (and, changes to the suit he wears on the ride).
But that's my more..personal idea of what the hell they 'should' do for if MCU comes to USO.