Do airline dispatchers pre-block seats for weight and balance on large wide body aircraft? I was reading a Oman Air flight review and one of the bits intrigued me:


  I had earlier used ExpertFlyer to monitor both how busy the flight
  would be and the seat map. I selected a window seat when I checked in
  and noticed there were plenty of empty seats around me. On the day of
  the flight, I noticed the two seats next to me were showing as
  blocked, which I assumed was part of a weight and balance exercise.


This review is for a wide body aircraft (Boeing 787 Dreamliner) and I am just wondering if Dispatchers ever block seats for weight and balance like the review writer refers to.

I mean I have often seen large blocks of seats not available for selection sometimes in the online interface but I always assumed this was for commercial reasons and not technical. In smaller flights I have seen passengers being moved around for weight and balance but is this also done in the large wide body aircraft?

Does anyone know?
Yes sometimes, because with most aircraft you can't fill all of the seats and all of the fuel tanks and stay under max gross weight, meaning the airplane can't achieve its potential maximum range with a full cabin and on long range city pairs some sort of passenger/fuel horse trading may have to go on.  

So on flights where the airplane needs more range that it has with a full cabin, it may be forced to limit seats filled to accommodate the extra fuel, and it will distribute the empty seats throughout the loading zones to prevent load concentrations for balance reasons.

You will also see seats blocked off to accommodate dead heading crew, but if you see a significant number blocked off in each cabin loading zone, and the seats are still empty when you board and its a long flight, it was probably due to fuel requirements.