I guess the point is, that Boeing IMO will sooner or later have to create a serious 300-350 seat 8000NM competitor. The 777-8i seems to become a heavy, expensive niche ultra long haul aircraft.
The 787-10 will be very efficient but doesn't have the payload-range needed to fly from hot Asian runways to Europe and the US.
It is reflected in Airbus taking over most 777 operators over the last few years.
Boeing will be the last to admit, but they seem to have lost the center of the big twin segment to Airbus.