What exactly is the situation regarding booking QF flights with Avios?

Been looking, out of curiosity, at HKG-SYD in F and there's nothing other than the odd Premium Economy seat coming up.
99% of all results are CX to SYD; CX to MEL and then QF to SYD.

Did look at LAX-SYD and actually found a seat in F. Clicked on it to see the cost and some error came up.

So, can BAEC members still use Avios for QF redemptions (I assume by telephone) and/or is any availability likely to "not exist" on BA systems?