An academic restoration of the United States' interiors, rather than a broad interpretation of what they once were, will present problems of its own.
In the context of her day, the interiors were quite remarkable. The queens Mary and Elizabeth had interiors designed around a conservative color scheme based on fluids your body produces while ill, while the Liberte inherited a big chunk of salvaged Normandie material- suitably garish and unfashionable- and subsequently looked like a fairly tacky brothel, and the Ile de France, as rebuilt, was just plain bizarre.
All were at least 20 years behind the times, stylistically.
Italia DID have a few liners on the South American run with airy, high-style interiors, but when the United States made her debut, the North Atlantic was still a fairly grim place to travel.
The impression that the United States made THEN, of brightness, newness, and lack of bordello-clutter, was quite striking. However, to current eyes, not used to enclosed-feeling ships with entire rooms furnished in shades of vomit, the impression will likely be one of an underfurnished formerly-deluxe motel in a part of town that the interstate bypassed.
So, should the interiors be literally reconstructed and cause people to think "It looks like a bad motel" or should they be interpretively rebuilt, with the trick lighting, bold colors, and very of-its-era artwork of the Italia ships? Or the cool, but in its own way lavish, elegance of the Scandinavian ships of the 1950s and 60s? Either way, it will be more crowd pleasing.... but academically dishonest.