They might actually be easier and cheaper to build than expanding the current underground network. And the LI Expressway is totally dysfunctional because it’s simply too crowded (for that matter, the trains are overcrowded too). So this really might not be a bad idea.
I’d have to see more about it, though.
Long Island’s becoming a basket case too. Now if they didn’t get rid of the Central Branch between East Garden City and Bethpage Junction (mostly removed when building Levittown, but a lot of the right of way is still there), they could have had an alternate rail line to Ronkonkoma and Babylon.