Sounds like a non-story to me. Or they could operate double pick-ups or double-drops - both inefficient, even if they don't involve 'empty' aircraft.
I'd trust the beancounters to work out whatever works best - and they can easily factor in the carbon cost, poor on TC if they didn't.
Of course, BA's ANU-SKB in a B777 is just 60 miles, pax usually in double figures - but Torygraph readers use that service (and there seem to be good operational reasons here too).