Is this range contractually promised? And with full loads and IFR reserves? Not to say against prevailing winds. Unless the answers to these questions are all yes, people can put down their Great Circle Mapper route planning. While the jet stream makes it easy to fly eastbound TATLs to pretty much every place in Europe, you need to be able to get the planes back, and without stops.

Note, too, that additional crew are needed as flights exceed 8-9 hours. While an extra FO on a 777 may add little extra cost on a per-pax basis, it will add a lot more on a A321XLR. Further, there is no dedicated crew rest, so J seats will need to taken out of revenue service.

For the above reasons, I expect the A321XLR to be used very similarly to how the 752s are today, and maybe used to add some extra frequencies at off hours -- say daytimes to CDG, FRA or LHR not just from EWR, but also IAD or ORD.