Yes of course. I’m sure the Mint is right on it and today’s minimally-staffed and much reduced in number banking branches will be able to cope with a sudden influx of coinage over the next working day.
When they switched to decimal currency, it didn’t just happen overnight. There was an official changeover date, but there was no way the old currency simply disappeared from one day to the next.
Likewise with new decimal tender, i.e. the transition to polymer notes, the 12-sided 50c replacing the round one, or the one and two dollar coins replacing notes.
In reality there will be a transition over the next 12-24 months or thereabouts. Who knows, the monarch’s visage may disappear altogether from Australia’s currency, even before we become a republic. Now might be a good time to do that. But I suspect they won’t.