Surprisingly the only abdicated Dutch monarch to retain the style of Majesty and King was King Willem I who became HM King Willem Frederik of the Netherlands once he signed the act of abdication in 1840. His son became HM the King and his daughter in law became HM the Queen. Queen Wilhelmina did not inspire her abdication on her great grandfather as he abdicated in troubled times. He himself would not accept the independence of Belgium and yet wanted to marry one of his late wife's Catholic and Belgian ladies in waiting.
Wilhelmina went further back in time and was inspired by emperor Charles V.
In the Netherlands even high ranked officials mistake the constitutional term King (meaning Monarch with the style of King or Queen) with the actual title.
If all of those politicians and officials who brought the argument that in the Netherlands there can only be one king had learned their history we might have had a different situation at present.
Had we punished them with no income or pension the state could have easily afforded to buy and restore Soestdijk Palace for the monarchy.
But unfortunately ignorance and stupidity rule in many countries and my own nation is not exempt from it.