Yes, you can get it on a rewards flight. They can do all sorts of weird and wonderful. I have seen reports of them refunding points (if you used AA) or dollars paid, booking you in a higher class on a later flight, paying for hotels, meals, taxi's AND giving you compensation (apparently $600-$800 is the sweet spot to get other bonuses). It does appear that the rebooked flights also earn points/credits. I just did LAX-ORD-BOS-LGA-MIA-PTY-MIA-TPA-DFW-LAX and every single flight was 100% capacity. I wasn't particularly listening but heard at least a few offering compensation.
In saying that, looking at loadings on SYD-LAX, they are 2/3 full most of the time. It is not a heavily loaded route.
I got bumped last year on a SFO-LAX flight that was a confirmed upgrade via SWU. I got a $300 voucher and put on next flight. It was totally fine - just spent a bit more time in lounge and got $300 for basically an hour of my time. Win!