Source: On Apple.
iFixit does a teardown of pretty much every Apple hardware that comes out. And what they found surprised them but it makes sense for Apple to include it? NFC in the new iPad Air 2.
Consider the importance of Apple Pay as a money printing scheme to pad Apple's Everest-like pile of cash, the iPad Air 2 and probably a future updated iPad mini sporting NFC makes it very important as a means for the tablets to serve as digital payment readers.