My 1st QF flight is coming up this week.

1.) I booked through AA.com on QF coded-flights, not AA-coded in Y (in the lowest fare class; O) on the 380 LAX to SYD this coming Sunday.
2.) Y is completely sold out. It's booked to or above authorization (i.e. severly overbooked)
3.) I have my AA Plat (aka 1W Sapphire) number in the res
4.) I dont have a seat assignment

What are my chances of an op-up?

Am I better off not trying to get a seat assignment as it would make me more prominent on the list of possible op-ups?