NPIP requirements vary from state to state. I don't know what Arizona requirements are and I don't know the requirements in the state the breeder you are talking about is in. To be certified in a state the breeder has to meet the requirements in that state. To be legal, they also have to meet the requirements of the state they are shipping to. Some are legal, some are not.
Different states require different things. About the only disease in common they all test for is Pullorum. Some states require testing for other things, some don't.
NPIP has nothing to do with vaccinations. The flocks are tested to see if they have Pullorum and they are restricted to getting chickens from other NPIP sites. Some states require testing for Pullorum and other things. You really need to talk to the breeder about what NPIP means in his/her state and how he/she is complying.