Not necessarily. JFK/YYZ-HKG usually adopts the polar route. But HKG-YYZ/JFK not necessarily the case. Sometimes going east, they adopt the strong tail wind and fly across the Pacific and then cross their way into NA near the U.S/Canadian border. This was certainly the flight path when we took CX826 in F back to YYZ on Sunday along with some other HKG-YYZ flights we've done in the past with CX and AC. This type of routing was also the case when I flew KE's ICN-YYZ in 2009.