That's cause even you Pomms have moved to Metric.... I think its Burma, Liberia and the USA who are the only countries that haven't adopted it.....
As a point of Interest, you can still buy a Pint in Australia. You can also get Schooners, middy's and Pots, of course it depends roughly on where you.
Most of Australia considers a Schooner 425ml and a Pint 570ml... Cept Adelaide... for some reason their schooner is 285ml and a pint is 425ml and the IMPERIAL Pint is 570ml.
Now a 285ml drink in Australia is a bit more confusing in Melbourne and Brisbane its a Pot, Canberra Perth and Sydney its a Middy (or sometimes a half pint), and of course the aforementioned weirdness of Adelaide calling it a schooner.
Oh and if you are in Hobart, a middy/pot could also be known as a 10, and a schooner a 15, as in 10 and 15 ounces.
Of course then you have the bottles.
A stubby or can is 375ml (usually) and a Tallie is 750ml,
Of course the most important measurement is the NIP, which the real drinkers use.... 30ml of spirits...
And as always Drink responsibly