After reading this, it sounds like you just need to show your vaccination card if you are vaccinated, and it not, your back to testing again. A brief mention the Dutch side would be implementing something similar... If I may proffer a thought, I think that this is in response to the Dutch side news yesterday, High season coming up, and driving who would stay on what side with 'different' rules in place (as of yesterday) to bad we are involving peoples health in tourism $$$- just my initial thoughts, always a prerogative to change ones mind..