Removing feral animals is difficult, especially cats, see:
http://www.australianwildlife.org/field-programs/feral-cat-r...
So it is being done, however, to truly remove cats, it needs to be done in an fenced off areas(or islands). Fence maintenance is ongoing and expensive, plus Australia is a big place:
http://world.bymap.org/LandArea.html
While the AWC approach is effective, it will take decades and huge investment to scale out across the continent.
If small scale experiments like the article describes show promise, it might provide cheaper and faster methods for mitigation (not elimination) of the impact of feral animal predation on native marsupial populations. Hopefully enough to keep the marsupial populations viable in more areas.
Sometimes fencing an eradication are not effective tools for feral animal removal.
Eradication and containment efforts for preventing the spread of cane toads (another introduced species gone feral in Australia) have proven ineffective despite significant investment and effort. This is largely due to cane toads being able to move great distances during the wet season when large areas of northern Australia are flooded and their ability to breed in great numbers.
Research into training quolls to avoid eating cane toads by feeding them cane toad sausages with small amounts of a nausea inducing agent have show promise. Enough to make them unwell, but not kill them.
https://www.australiangeographic.com.au/topics/wildlife/2017...
http://www.reptilesmagazine.com/Aussie-Authorities-Expand-Ca...
I have done off-track hikes through the Kimberley region in Western Australia over the past few years. Cane toads reached the Manning River (central Kimberley) a couple of years ago. On this years hike there was a noticeable decrease in the numbers of native animals (fresh water crocodiles, snakes, long-necked turtles, goannas, fish etc - we don't tend to see many marsupials as they tend to be noturnal) in the Manning River region.
As eradication and containment are ineffective tools for cane toad management, I'd say any research into alternative programs for improving long term native animal survival against feral predation/impact is a good idea.