I didn't realise Margrethe II never paid a state visit to The Netherlands during Beatrix' reign. Quite odd indeed.
I am curious to see if the Netherlands will be receiving many incoming state visits the next years. In a few weeks we will have a new coalition government with an extreme-right party as it's largest partner. I imagine some countries will prefer to wait until that is over so they will not have to associate themselves with that. I do not know enough about Danish politics if such a visit would be considered controversial by the government.
I imagine the King may visit Germany soon. It will be an important partner and neighbour for Denmark. Of course Queen Margrethe II was there not too long ago, but considering Germany's importance in Europe it is a country they can't visit enough.
A state visit to the UK within the next couple of years would be wonderful.