I guess they are refering to 'narrow casting' rather than 'broad casting', as these stations won't generally be receivable on a normal radio in Australia & New Zealand.
Although the band is 531–1701 kHz with 9kHz spacing like Europe there are a few low power stations above 1602 kHz for things like weather, traffic and tourist info.
I my experience of travelling in and around NSW, car radios stop at 1602 and like everywhere else in the world folks aren't buying new AM radios, it's FM and DAB all the way.