The process will never translate to construction costs in the US unless a temporary worker visa is made into law that would allow us construction companies to pay a worker 5 dollars a day for a 12 hr shift. Even if such a law was passed, I don't see the Unions in NY letting that happen.
I also believe it is disingenuous to say that the building will be done in 90 days. How long to build the prefab parts? How long to finish the interiors so that the building is functional? How long to finish the flatwork and landscaping so that the approach to the building is functional? Is construction of the foundation included in that number?
I recently turned down a project in Malaysia and even with a large population that was looking for work the Malaysian contractors imported workers from Indonesia. They worked on site barefoot and their safety goal was to limit the deaths on the site. Their temporary barracks looked like something straight out of "Hell on Wheels."
It will be an amazing feat if they pull it off and prefabrication is definitely the future of construction, but I'm definitely skeptical.