Well, normally optimum flap setting will be used, as far as I am concerned and what I've talked with friend, optimization is what the airline and pilot is looking for. Why would you put f2 when you do not have anything on the flight path and not limited by any means?
The only reason ( there's more but in this case...) I could think of to put f2 is being speed limited on SID ( often with the 321LR) other than that runways are usually long enough to put f1, also middle East might be due to the temp I guess.