Earlier today, T-Mobile announced that subscribers to its Simple Choice wireless plans would soon be able to make calls to/from, and access 4G LTE data in, Mexico and Canada at no extra charge (though you do have to take the step of opting in to the new plan). But what about those T-Mo users who have been holding on to their pre-“Un-carrier” plans? If they want access to this call-anyone-in-North-America option, they’ll have to ditch their old plan or pay up. [More]