I live in the Netherlands, play poker online on various sites and don't pay taxes over any of my (albeit meager) winnings.
I am not a tax expert, Dutch tax legislation on this subject is vague at best, and if you are a pro poker player planning on moving here you should definitely consult a local tax lawyer before doing so.
Anyway, the way i understand it is that, officially, all winnings from online casino's within the EU are tax free. However, there is some discussion about which sites are within the EU. In june, the dutch tax agency released a list of sites they consider within the EU. You can find a copy of that list here: https://nl.pokernews.com/nieuws/2016...unie-24981.htm
For instance Pokerstars.eu isn't on that list and the dutch TA expects you to pay taxes over your winnings there. However you can appeal to this and there is significant precedent (see the link you posted) that those appeals would be succesful.