While not any app can access the NFC in an iPhone directly, any entity can leverage the NFC via Apple Pay. I have plenty of reward cards, even tickets, airline tickets, etc. in my Apple Pay Wallet. What Apple requires for an entity to be in the Apple Wallet I don't know, but I don't believe they are stifling innovation. Feel free to correct me if I'm wrong. I just haven't heard of anyone being turned down to be part of Apple Pay.