Maybe CX thinks there is a lot of demand for ex-CAN flights to say JFK or SFO? Somewhere CAN doesn't offer direct access? I'm pretty sure UA never started the SFO-CAN service they got approved for, and to get to JFK you need to route via somewhere like NRT. So now maybe CX can sell SFO or JFK-CAN and just use the KA flight to shuttle pax from HKG-CAN? Either way I'm not sure I fully understand it