That may be true for CX (I don't really know) but QF? QF has a long-standing reputation for allowing seats to go out empty rather than open them up for award tickets.

Case in point - flying BNE-MEL a few weeks ago on a mileage ticket in J on a Saturday afternoon. We get to the airport early, in time to catch the two+-hours-earlier-than-our-flight previous flight. Enquire as to availability on that earlier flight. Get a curt "not available." Dealing with QF I've learnt that it's a waste of time to ask "OK, there may be no award seats in inventory but are there open seats <<there were it subsequently appears at least 5, based on what they were willing to sell>> and, if so, would you please call and see if they will open up two of them for two oneworld Emeralds, so we don't sit in your lounge, eating and drinking at your expense for the next two hours." Would have been a win-win all round. QF? Not a chance.