AMD like Nvidia will give you the performance they think is worthy at the price point. if they want to slow a card down by giving it lower Pci-e bandwidth they will do so. Why cut back the chip more when they can simply limit it through the interface if indeed the card has more to give in the first place.
But I won't buy. Because the decision about the purchase comes from me, it is not a process with one direction in which AMD dictates all conditions. It isn't ok and is ugly.