Once they correct the mistake, those notes will be worth a fortune to collectors in a couple decades. Collectors love errors. And since the history is well documented online you get a bonus of free provenance.
They don't plan to recall them. Collectors love errors mainly because they're rare. There's 480 million of these and they'll never be worth much more than 50 AUD.
As someone has already stated, they recycle these notes as well. Even though they're plastic, they won't last forever. It doesn't help they're high denomination and therefore less used, but I wouldn't be surprised that after about 50 years, there will be a lot less of these.
They'll be even more rare in an un-circulated state.