Received an alert for this. US stock with conflicting messages regarding whether Samsung Pay works but a no brainer at this price with Amazon support.
EDIT: I've found this link hopefully it'll be possible to change region on the Watch3.
EDIT 2: For anyone who returns to this post, I just received my watch and was able to change the region to Australia following these steps: https://www.youtube.com/watch?v=EsshQ1-UIoY&ab_channel=Techn...
Samsung Pay successfully working!
Edit 930pm: 41mm on backorder.