IME, its only on some routes that it will do this. I think some routes into Scandanavia on SAS (that was burried in another thread somewhere). And I was able to get the site to bring up YYZ-YUL flights on AC. But I've definitely looked up other international routes and getting the there are no flights between these two cities, even when there is a non-stop *A flight serving the route. In short, it depends.