Garry Williams should be able to hear his ABC at night on their medium power, medium wave stations; I think they still exist.
I don't know where Garry Williams lives, but if he's far from a small Outback FM outlet, it will be his only option, and hopefully he has a really good MW radio, like a Superadio, CCRadio or PRD5.
Most of the powerful ABC 50 KW outlets are in the capital cities. Outside of the capital cities, it's all low power FM and AM, at least according to this list:
http://www.abc.net.au/radionational/frequency/
The "frequency finder" page on the ABC site is interesting. By just typing in a couple locations, you can get a small list of nearby ABC outlets, which show up on the Google map and you can see the coverage outlined in red. Most of the smaller outlets seem to be LPFM.
Knowing that Australian MWDXers get a lot of stations from other parts of their country, I'm guessing that some of the big city ABC MW outlets are audible in the Northern Territory and other Outback areas...
Maybe the Outback will see a surge in sales of CCRadios and PRD5's.
Just another example of why MW / AM band broadcasting is important.
PS -- from perusing the coverage map page, ABC Digital radio is only available in the five largest Capital cities. Of course, that's where most Australians live... but just sayin'. DAB was one of the reasons given for yanking the plug on the NT SW service.