Maybe in the case of the BBC. All of the Major US producers make any audio description they produce available to Canada. And we also make any audio description we produce available to the US, though it's often not broadcast, because the US has no similar law. However, if a show is so popular that a Canadian station is going to go to the effort and expense of purchasing a license to broadcast it from the BBC, I doubt the small added cost of producing audio description is going to be the deciding factor. Doctor Who, for example, is an international sensation. What TV station is going to say "Nope. I'm not going to spend a few thousand dollars to produce audio description for a show that several million canadians will watch." If a station is stupid enough to do that, some other station will pick up Doctor Who instead, and happily take those millions of viewers. Maybe it means that we in Canada don't get to see some of the less popular shows from the BBC. But then, if the show isn't hugely popular in the first place, why would a Canadian TV station bother buying a license to broadcast it?