Yes, looking some more it does seem like it's whatever is convenient for the owner. I still like that the flock is tested for at least some things. I wouldn't think people would pay for the tests if there was a chance the flock would fail.I've bought from a couple NPIPer's.
One wouldn't allow me anywhere near their coops, said it was against the NPIP rules. Another wouldn't allow me on their property, said it would involve protective clothing, disinfecting of shoes and shoe covers so we met in a public parking lot.
NPIP overall is pretty loose with no real compliance checks, just some testing each year by anyone who wants to pay for the training(not even sure what that consists of) and only word of honor of compliance and a closed flock.