Yes, definitely! In fact I think straight-out-of-school people are almost the minority in my year. You can do a year of something else (or two, or however many you want really) and transfer in. You'll still need to do the UMAT and everything, but like that you can get into an undergraduate degree.
There are also many medical schools in Australia that only offer degrees via a graduate pathway (so, you have to finish a bachelor's degree - most people would do medical science or science but you can do whatever you want) and then you do the GAMSAT (which is a little bit like the UMAT except on steroids - it takes an entire day and has a science, essay, and logic section).
Although, if you're able to, I'd still recommend giving the UMAT a go this year because you never know. It's quite difficult to guess what ATAR you'll get and often people seem to think they won't go as well as they do. Good luck!