Currently, Australia has an arrival cap, but no official cap for people leaving the country.
If you do not intend to come back for the forseeable future (next year or so), and you have a pretty good chance of getting an exemption to leave the country, there isn’t too much risk in booking a flight. And because it’s booked with points, its actually quite a bit more flexible than cash. Worst case, just pay the cancellation fee and you’ll get the points back.
The main problems now are really about being able to leave the country in the first place, and coming back once you’ve left given the strict caps. If your situation avoids both those hurdles, I don’t see why you shouldn’t go for it.