I disagree with most of this, respectfully. Like Tented, I think Novak very much cares what people think of him, and he rather blatantly courts the affection of the crowd. I also disagree that this is going to reflect poorly on Australia, though the tournament (esp. Tiley and Tennis Australia) will probably get a dent. Definitely I think that Covid restrictions are too tight, in general, and are against vaccine mandates, and, for them, there will be a great deal of sympathy. But there are a lot more people, in and out of Australia, who see this as a tennis player looking to get around the rules just because of his own beliefs, and some feeling that he ought to be able to, because he's #1, or etc. Who think that Australia is doing the right thing by insisting that the rules (agree with them or don't) apply to everyone.
It will remain to be seen how other tournaments will react to this kerfuffle. The first thing that is a wait-and-see is what the regulations will be per country when we get there, because that will supersede what any individual tournament decides to do. And then we'll see how far they are willing to go to accommodate Novak, if he remains unvaccinated.