Netherlands supported every anti-Brexit development thus far, now supports delay for self-interest because a no-deal Brexit will hit them the hardest

https://www.nu.nl/brexit/5833767/minister-blok-uitstel-van-brexit-is-ook-in-nederlands-belang.html

Guess after effectively killing democracy and publicly humiliating their country on international stage after the Ukraine referendum, supporting the same in England is a lateral move ;)
https://www.dutchnews.nl/features/2016/01/83847/
https://euobserver.com/beyond-brussels/141070

Regarding a no-deal Brexit and the consequences; It will cause damage to England indeed, but will absolutely DEVASTATE the EU. Not only regarding the direct damage (estimated 3 billion Euros per year to the Netherlands alone) but more importantly, the facade about ''unity'' will be exposed for what it is when they start to turn on each other each for the well-being and prosperity of their own country rather than the EU as a whole, by wanting to create preferential trade policies with their closest and most important neighbors.
https://nltimes.nl/2019/03/21/deal-brexit-will-cost-netherlands-eu3-billion-per-year-german-think-tank

Keep in mind that after England's exit, the Netherlands who will loose 3 billion a year, will then be FORCED TO PAY EVEN MORE to that same EU, who will then continue to redirect that money to the failing economies in East-Europe.
https://www.express.co.uk/news/uk/1002606/Brexit-news-UK-EU-no-deal-hit-Brussels-harder-latest-Theresa-May

Estimations regarding Germany, the biggest financial contributor to the EU, are a staggering 15 billion Euros extra per year.
https://www.express.co.uk/news/world/1035385/Brexit-news-Germany-EU-budget-UK-deal-latest