The real reason for this second withdrawal is the fear the Australian government has that Djokovic will cause even more locals (formerly known as citizens ) to dig their heels in - over being required to be jabbed with ... It has zilch to do with health. It is all about the control.
I'll admit it is Austrailia's call because he is not a citizen, and it is their border. Think of how torqued the CITIZENS, who are almost imprisoned, would react. And who could blame them?