JAL Shell Flat Seats are available on all flights from NRT to SFO/LAX/JFK/ORD. The only flights that don't see the new shell flat seats are YVR/MEX and HNL/KOA flights.
Yes, all three CX JFK flights will see the new business class seats but for CX 888/9 via YVR, last minute aircraft substitution may happen.
One more difference - CX offers a proper amenity kit, but JAL offers slippers and a tray of amenities.
Carfield