As discussed many times, YYZ is not the most profitable destination for CX so that is why they took out F Class and use the 34D instead.

Highly unlikely will they reinstate no-stop to YYZ as the demand is not as great as JFK and CX have better use of their limited 346 at present.

Maybe when they get some new LR/ER aircrafts then YYZ non-stop might be back on the agenda.