When you exclude Brooklyn and Queens, which are ~70 miles away from this site, Long Island has only (7568304 - 2532645 - 2247848) = 2.8 million residents. And that 70 mile distance will be far enough out of the way to exclude most out-of-area tourists who are visiting NYC.
The site significance is cool, no doubt, but I question how many people will ever trek out to visit this.
Eh, 70 miles is still daily commuter distance; there are thousands and thousands of people who commute daily from 70+ miles away in Long Island, Connecticut, New Jersey, Pennsylvania, and Upstate to Manhattan.
A good science/history museum there would still be in range of the informed tourist (ie, those likely to spend a day at a Tesla museum) and more importantly of elementary school field trips. Personally I would pair it with the Teddy Roosevelt museum on Long Island and do a Turn-of-the-Century Internet Celebrity Day Trip.
The site significance is cool, no doubt, but I question how many people will ever trek out to visit this.