Sadly you have a double whammy!
If you could get to a REAL Apple Store then you could argue with them directly in person. Apple can at their discretion forgo the fee's and parts costs under a 'warranty exception' but you need to fight for it! As you don't have one in NZ that's not possible.
Here you have no recourse! The system will be shipped out to the repair depot and no way to talk to any one there! And talking over the phone to anyone likely sway won't them.
While its still not possible to travel due to COVID is there anyway you can get your system to an Apple Store in Australia? Either having a friend be your proxy or if you can, get there your self to drop it off?
Do keep in mind you'll need to stay awhile or have made arrangements for someone to pick it up. Make sure when you do drop it off this is documented on the repair slip! As the alternate otherwise they won't give it to them) and no they won't ship it to you afterwards. That still doesn't guarantee Apple will cover it, you may need to walk up the food chain to get that yes you want. Talk to the service manager then store and then regional managers (service and store) and lastly corporate.