Let's be realistic.
CX only flies 4 weekly to JFK, 3 weely to LAX and 2 weely to SFO.
The situation is getting worse and worse for CX and their traffic is down to a trickle.
The situation "might" improve in six months and they might reintroduce one flight with F.
But they only have 6 F seats. The demand for awards F seats will be large and CX will prioritize revenue tickets. People have tons of miles and few ways to spend them.

It may be a good idea to book on flight numbers currently operating. But if CX reintroduce F on one 77W, they might change the schedule.