King Willem-Alexander shows retrained to fly a Boeing 737, according to well established site Aviation Watch. Now the king is still active as a Fokker 70 pilot, the device Netherlands as government aircraft. Retraining suggests according Aviation Watch that the government unit PH-KBX therefore be replaced by a Boeing 737.
Since King Willem-Alexander behind closed doors talked with the supervisor during his visit as Prince in 2012, the rumors that the Netherlands had chosen Embraer.
Now the choice of Boeing seems to fall, the flight experience of the king must keep pace. After all, he creeps crawling regularly at the controls of the current government unit and he will want to do that in the new plane. So he puts on destinations of his state visit often itself the Dutch unit on the ground, behind the cockpit window to wave his greeters.