When Apple make a statement I'm interested and believe that they want to make things better for their customers. When Westpac make a statement I believe they are are not in the least bit concerned about their customers, only their share price.
Apple counts on such naivety. They make money selling your own bank the ability to let you access them on your own device, and you happily don't even realize you're a product.
I'm not sure how letting banks do NFC from their own apps, bypassing Apple Pay, would benefit consumers however. Are Apple's fees for Apple Pay excessive?
In some countries Apple's original US demands definitely are impossible to meet. Even in the US, used to high fees, Apple's fee (for essentially doing nothing during a contactless transaction) harms smaller banks and credit unions.
If a bank has to pay more for a transaction, customer extras like purchase awards can sometimes no longer be funded.
Another benefit to the user: more bank choice almost instantly if banks did not have to pay the Apple user access ransom. Look at how their fee held back adoption already.
How would this even work if Apple doesn't let you change defaults? Apple Pay would still be triggered from the lock screen. And if I need to manually unlock my phone and open said app, that kinda defeats the purpose of said app to begin with.
When a device gets near enough to another device or terminal to initiate communications, the two sides negotiate which app to start.
Regular open NFC implementations allow device apps to register their Application ID. So, for example, a contactless Mastercard payment works the same way it does on an iPhone: all the following communications are routed only to the Secure Element or wherever the Mastercard payment app(let) resides. But if it was a bus NFC point, your corresponding transit app would open. (In London, your Oyster app would open.)
There are also standard ways of one device telling another that it wants to send a short communication, like a URL, contact info, map address, directions, or even open a Bluetooth / WiFi connection to transfer larger media.
All that is possible and done today on Android devices.