I'd be almost certain that this was discussed when renewing their exclusivity deal. However, your phrasing implies that you think Apple is "stuck" and getting

I'd be almost certain that this was discussed when renewing their exclusivity deal. However, your phrasing implies that you think Apple is "stuck" and getting shafted by AT&T. Really, it is quite the opposite. Apple surely looooves the exclusivity deal because they can leverage it over AT&T to collect globs while AT&T eats the cost over the life of the subscription. The exclusivity deal is one of the key reasons that Apple is able to offer such fantastic hardware at their current price point.