Outbound on a Fridday and return on Saturday? Level 1K?
Slim chances that the upgrade will ever clear .
While LAX isn't nearly as bad as SFO, Oz is a vacation destination for gazillions of GS and their entire families - a 1K has limited chances to get an ug against them.

I failed around 40% of all my upgrades SFO-SYD/SYD-SFO and I pay a lot of attention not to fly on the busy days of or into the weekend. And I always book reasonably far ahead.

I'd prepare myself for a cozy ride in E+...