I think that any routes that go through Canadian or Mexican airspace (ie routes like ORD-BOS and sometimes ORD-SEA, MIA-SAN, and anything to ANC) would require the approval of those aviation authorities; I remember noting that the Canadian ban at least prohibited the MAX in our airspace. Certainly an issue AA could avoid by choosing which routes they use the MAX on or by choosing the flight path to stay out of Canada/Mexico, but a consideration. And of course it wouldn’t be a good look for AA to be flying a plane that has not been approved throughout the developed world due to a major safety concern. And no MAX on international routes to countries that haven’t approved it, most likely.