I suspect, as with LX, that EK is using the planes thay have available and those happen to have a F cabin versus actively seeking out F class. Anybody actually buying F is the cherry on the sundae and not considered in their route planning (or very little). If I recall, their their non-F cabin A380 is the super high density one which is most likely best served by other markets.

If there was an F market in Canada, AC would be the first in line to exploit it. And given that over 50% of AC's traffic is not O/D in Canada the overall market for F is probably also limited.