If Australians are legally obliged to implement back-doors on behalf of the Australian government and not mention it to their employer, why would any of these tech companies want you?
You'd be a massive security liability to them.
I left Fastmail over the recent Oz decision with encryption. I was a paying customer since 2002. It pained me horribly to leave, but I had no choice over principle.
Other than diplomatic norms, once a person leaves a country, he is bound by the laws of the receiving country. I base this on common knowledge and also having lived in 5 countries myself.
Australia and New Zealand are rapidly becoming draconian. I have friends in both countries. They are thinking of leaving because of all of this. The entire knee-jerk reaction to guns in NZ is but the latest in a long line of stupidities the Kiwi and Aussie governments have been up to. For example, in NSW, if you have a knife painted green, you can go to jail because it's a "zombie knife". Think I'm joking? Look it up. The last "free" state in Oz is QLD. The rest of them are up to their necks in draconian stupidity.