A350 overweight?

Airbus quietly unveiled new payload-range data for the three A350 models on it's website.
The A350-900 now seats 315 (was 314), but flies 350nm less: 7,750nm.
The A350-800 now seats 276 (was 270), but flies 250nm less: 8,250nm
The A350-1000 now seats 369 (was 350), but flies 400nm less: 8,000nm

As this comes about 5 months after first flight I guess it has something to do with the initial performance of the aircraft. What it is exactly we cannot know. It could be:
  • higher than anticipated SFC of the Trent XWB engines
  • higher aircraft weight which now became clear cannot be brought down
  • aerodynamic inefficiencies
What strikes my eyes that the one more passenger in the A350-900 (for whom we suggest a generous extra weight of 300lbs including seat etc.) costs more range than the six passengers more in the -800. And the 19 extra passengers cost only 50nm more than the one passenger in the -900. Although the -1000 is structural different than the -800 and the -900 and the engines are different too, this is not really conclusive.

I guess we can expect some argueing duels between John Leahy and Randy Tinseth over these new numbers in Dubai next week. Randy will not miss out to bash the A350 for ranges that are (nominally) again not meeting Emirates range expectations (DXB-LAX) whereas "his" B777-9 will do so (although I would expect Emirates to fly these long routes with a 3 class layout with less than 350 passengers in a A350-1000). And John Leahy will try and find a way to spin something positive around these numbers...

UPDATE: in fact these numbrs are NOT NEW and where already shown in 2011, long before the first flight and probably also the SFC of the certificated Trent XWB became clear.