I read with interest the complaint about the shift shudder in a Nissan Navara, as I too have the same complaint about my 2012 Navara Dual-Cab 2.5 auto five-speed. When I first contacted Nissan about I was told that it was tuned to international specs, whatever that means. After reading about the other report I went back to Nissan and was this time told that they had only one other complaint and they said that it was a "characteristic of the car"! I'm not happy.
Like every car company it would seem Nissan is doing everything in its power to reduce fuel consumption and holding on to higher gears for longer is a way to help do that. Go back to your dealer and ask if they can "retune" to get rid of the shudder.