787?
Maybe they don't want the risk of a plastic fuel container.
UAVs are taking over faster than most people seem to admit. We don't need a $350 Million 21st century F-22 manned fighter against a medieval foe. With the fighters go the tankers.
It couldn't be too tough to convert used 757s. They're even the same fuselage as the KC-135. They would be good for another ten years or so.
Without worthy enemies, the Air Forces are just very expensive flying clubs.
GB