I'm hoping to fly RDU-JFK-EDI in WT+ in December, but I'm really only interested in experiencing the new seat as the old World Traveller Plus seems a little dated. I'm not a frequent flyer and I just want to pay the (slight) premium as a treat to myself, but I believe the new seat is only available on the 777-300ER and *some* of the 777-200s.

My question is, how likely is it that the JFK-LHR route will feature the new seat? The BA website only specifies that the route is served by a 777, but doesn't specify -200 or -300ER.

Thanks!