I'm flying CX ORD>F>HKG>C>SYD in October. Could not find anything on QF in F/C, and won't fly Y. Started looking in Feb. Had my assistant checking every hour for a few weeks. Nada. I did grab QF SYD>C>DFW for the return. Beats the SYD>HNL>LAX combo that came up when C was listed as available.
I read in an Aussy FF site that QF A-380 (or most) F isn't avail for AA. 2010 I landed QF F ORD>LAX>MEL>C>ACK. Routed back thru SYD. The F lounges in MEL & SYD are worth the extra miles. Good luck in the search.