Business as usual, in other words.
If it's any consolation, there's pretty good odds they'll quietly shelve this latest brain fart after the election - especially if it starts causing them polling pain. Chances are it's all about padding out the upcoming Budget bottom line - it's not actually supposed to work (whether it does or not is irrelevant), as long as they can use the phantom savings/revenue to make their ongoing fiscal incompetence look a little less dismal.
"Oh yeah, Amazon and eBay will totally do all the hard work for us, and it'll bring in Eleventy Billion Dollars worth of extra GST revenue!"