Originally Posted by
SonicStar817
As far as I'm aware all the JFK flights are listed to be operated with Club Suites by then. However, the roll out has slowed as a result of covid, so all the 777 aircraft may not be done by then as originally planned. At the moment, most of the GE powered 777-200ERs are completed, so you can book JFK flights with the 49J cabin with a relatively good chance. Of course everything is subject to change.
There is absolutely no certainty 10 months out of a particular aircraft type operating a specific flight between JFK and LHR. There were regular aircraft swaps previously between 747s and 777s so there's nothing to say that a flight scheduled as a 772 won't swap to a 773, so there is always still the risk of a CW cabin appearing on a non-reconfigured 772 or 773.