I think they said the runnerup will host BUT Australia's TV station will get a lot of say in the presentation. So they'll both be allowed to run their ideas for the next Eurovision.
The full version reminds me of "Undo" by Sanna Nielsen, the Swedish representative of 2014 which ended up 3rd. I don't think it's as good as "Undo" but it's definitely one of the strongest songs this year.
So some of her Aussie stans that I know think she's keeping her voice milder in studio so she can completely blow away during the live performance. Perched for her live to outshine most lessors