I flew KLM last Saturday from France to AMS, with onward non-Schengen connection, and there was never any mention at any moment of any Dutch health form. Neither at my departure airport, nor at Schiphol.
There was an annoying extra security check (body scan and bag scan) after passport control to enter the non-Schengen terminal. They were sending only certain passengers through this additional security (which was very slow, because almost every carry-on bag was flagged for manual inspection, and there was only one person doing this job). Other passengers were allowed to go right through, without any additional security. No idea what criteria were being applied there.