This is where it starts to become highly political...
Should airports an their regulators worldwide decide to extend operating hours for quiet aircraft, potentially allowing for unrestricted 24 hours operation below a certain noise threshold, a completely new market may develop. A lot of westbound long range night flights may allow to travel without loosing a day, depart late in the evening or arrive early in the morning. And this level of noise reduction will probably only be possible with the GTF concept.