I think Qantas is now right on the money & we will be able to go almost anywhere in the world by mid Dec 2021, as long as you've had your shots.
However, I think instead of daily flights to LA from BNE, SYD, MEL, we might see Qantas start with say 3 or 4 a week & be routed via awful SYD other days. Demand will determine frequency & that all depends on govt announcements. If the govt says in July or August, everyone can go to UK, USA etc. if had shots, then that a decent lead time. If they wait until Oct, that's not much lead time.
So we can go to NZ now & Cook Islands is open to kiwis from next week (not sure if that means we can go to Cook Islands via NZ). Singapore, Fiji & many other places very soon. No restrictions now on us going to UK(no quarantine as long as have had shots) but we can't leave here, not sure why.