Right now it will likely work well. It is trained on a largely US based data set and so accents within that data set will do better, but the way the model works I wouldn't expect many challenges with Australian.

Interestingly, as we dive deeper into phonics and phonemes it will become more challenging as what may be correct for one accent, would be incorrect for another. We will need the ability to select - by child - what is 'allowed'. This applies to dialects as well.