I to would doubt EK would offer an onward connextion to NY, however the rumour I keep hearing and reading is that EK are constantly been asked for their ncl stats by a US legacy carrier. I read recently that EK are keen to see NCL offer westward longhaul services - not sure why though?
The only US carrier I can think of is CO, correct me if im wrong, as this is the only US carrier they codeshare with and therefore the one EK are more likely to provide with the commercial data a carrier is after.
With regard to LS not sure if a transatlantic route with them would work as I suspect quite a lot of pax would want a legacy carrier with onward connextions. This is afterall what is making EK so successfull