What do you expect? YVR + Y-class Visiting Relatives = low yield. So Air China put the Y heavy equipment on this route.

No, seriously, I think Air China will use the 3-4-3 two classes B77W on bilateral restricted and those stations does not make sense to have additional frequencies. Unfortunately YVR is one of these places together with Sydney in peak time. I think some US destinations will see these birds as well. No plan for these birds to Europe yet thanks goodness. But we stuck with ancient A332 in some cities.