You’re half right in that statement, NFC on iOS is Apple Pay only but the iPhone 7 is capable of reading and writing FeliCa cards.
That’s not what I’m thinking of here, though NFC card activation on Android would be cool, I’m thinking of the Monzo service being aware of what card was sent out to a customer by scanning the card before it is put in the post. There are probably rules around card number handling and issues with cards in transit that would prevent this from working smoothly though.