Incorrect documents or not, public pressure or not, you'd probably have more luck getting into North Korea than Australia. At least if you went to Pyongyang you could bring fruit into the country with you.
Unless he and his team have been bubbled off from the reality of Aussie customs for the last 10-15 years that he's been going there, it's impossible not to know how strict their customs checks are.
Complaining about how strict they are is irrelevant. Them's the rules. Nobody is forcing him to come to the tournament - it's not like he's desperate for the fecking money. But he seems more than happy to just idly go about his business putting others at risk (I know the vaccine won't prevent him from passing the virus about, but if he's antivax then it's not a stretch to assume that he also doesn't give a shit about preventative measures).
And the utter shite coming from his family is.... Well. Utter shite. He's a revolutionary and changing the world? He hits a ball with a fecking stick for a couple of minutes, puts a towel over his face for a couple of minutes, pretends he's got cramp for a couple of minutes, and grunts. Physically and mentally it's impressive as feck, but nobody looks at tennis and thinks "feck, the whole world would explode if we didn't play this".