I believe that is correct for larger (>30) accoms, per the link I posted in my earlier post' I don't see anywhere that it varies by nationality so for "Americans" presumably can read "visitors".
OP doesn't say but assuming they are arriving at PJIA on Dutch side they would only need COVID test if not fully vaccinated (per Sint M govt. here: )
TRAVEL REQUIREMENTS (October 22, 2021)
Definitely confusing, hope the OP got a response from their accoms.
Dave.