I don't think this is the case. From my understanding they only looked at persons that visited at least 10 different drop box locations and at least 5 non-profits. They also filtered out persons where this was their usual behavior before the election period.

https://www.health.gov.au/ministers/the-hon-greg-hunt-mp/media/press-conference-in-canberra-on-17-june-2021-about-updated-atagi-covid-19-advice

Full quote...

"It has been the difference in so many ways as to why this year, for example, whilst the world has agonisingly lost over 2 million souls to COVID, there have been no people who have caught COVID in Australia and passed away."

Only referring to 2021.