Australia will 100% not be swapping. There is zero debate about this, there is zero will and there are far more pressing issues to deal with than adding this significant cultural change.
And I have no idea why Japan changing would be the catalyst.
And I have no idea why Japan changing would be the catalyst.
Australia doing that would weird, as I think it'd an eight jurisdictions to sign up to it. That said, I can see WA doing it absolutely.