I have the same question as the OP. KLM sent me a message saying that I need a COVID test to fly to AMS even though I am only transferring. My journey is LHR-AMS-CPH and I know the UK is not on the safe list but neither is the US.

"The Dutch government requires you to show a negative COVID-19 NAAT(PCR test) result and a rapid antigen test. Having only a NAAT(PCR) test is allowed, if you have a transfer flight in AMS or if the NAAT(PCR) test is not older than 24h before departure."

I have sent a message to the Dutch Ministry of Foreign Affairs and they also tell me this:-

"You need a negative NAAT test outcome no older than 72 hours at the expected time of arrival in the Netherlands."

So I wonder if the change from the 1st June is the requirement for the two tests (one to arrive in AMS and the second rapid test to transfer) and now you can just have one? This is how I read it from the Schiphol website:

"Transfer passengers exempt from test requirement

As of 1 June, transfer passengers travelling via Schiphol are exempt from the negative test requirement. If you are staying at Schiphol during your transfer, you do not need a new negative COVID-19 test result. Your test result remains valid throughout your transfer, including any potential delays. "


Unfortunately reading the government.nl page on the rules for changing planes seems to be only half the story and needs to be read in conjunction with the general rule for arriving in the Netherlands, at least this is my conclusion.

Traveldocs did not say that I need a COVID test to enter or transit the Netherlands to add to my confusion.