I avoid them like the plague for this reason. Having your e-mail provider compelled to work against your interests is no joke and you may not want to be in that situation.
This is not quite true.
The TOLA bill does allow the Australian government to compel an employee to break their product's encryption — which, yes, is dumb as hell. But Fastmail does not offer end-to-end encryption. As an Australian company, they already have had to comply with a court warrant asking them to surrender data; in other words, law enforcement does not need them to install a backdoor when they already have a front door. Your comment implies that TOLA made Fastmail less secure somehow, but this has been the case long before TOLA; the existence of that bill changes nothing.
I feel like it's important to point this out, not for the sake of pedantry, but to say that if you want truly secure encrypted e-mail, you must be in control of the encryption and decryption step, rather that having a company do that for you — you can't assume you'll be safe just because your provider isn't based in Australia. It's been a while since I've looked, but I think it would be very hard to find an e-mail provider that explicitly says it won't hand over data when presented with a valid warrant.
It's probably worth thinking about that too before hastily switching email providers. Fastmail is a solid provider, with great support and I never had a real issue with them. I give them money, they provide me a good and stable email service.
"Australian intelligence services decline to comment on massive data breach."
There's a difference between "don't want their mail read" and "someone will be able to read my emails if there's a court order and they are interested in the content of my specific inbox".
If you use a local mail client that stores your email locally you'll also have access to all these.