Man, I'm not sure if you've heard but CX is one of the few airlines with exemption to fly over Russian airspace which allows them to resume with the Polar route just like the old days. Polar route flights were restarted around a year ago if I remember correctly. They could certainly send the 77Ws to JFK if they wanted to; hence the suspicion by me and several others that the reluctance by CX to do so is in fact a commercial decision. One poster above has also mentioned the 777 has been lacking a specific permit to operate over the Russian airspace since the pandemic until recently as another reason.