You would still be a resident for Australian tax purposes. However airline provides documentation confirming tax has been taken care of in China, where tax brackets are not too dissimilar to Australian. My understanding is the treaty ensures you pay only the difference between that and Australian tax, which amounts to pretty much nothing.
Whether any money actually changes hands between the airline and the Chinese govt is nothing for us to be concerned with. They've probably done a deal on the grounds of national interest so they can make it attractive to pilots, whilst at the same time incurring minimum cost. In the hand is all that counts.
My information is that some went to Air China a couple of years ago, based in MEL and SYD, and they are beneficiaries of a similar arrangement.
I did some figures as to what gross amount you would have to earn in Australia to earn US$17,950 pcm net. I came up with approximately A$400,000 per year, plus super. Don't trust my research. Plug it into the ATO tax calculator and see what you come up with.
Maybe the three year contract only makes sense for those in their 50's. Sandpitters wanting to come home, or JQ guys wanting a $tep up. Not sure about QF or CX...