Compressor Stall - I think you'll probably find that aircrew as a whole make up a very small percentage outlay of Qantas' budget; As such, I'd hardly envisage that Qantas has brand new hire Second Officers in line to be made redundant should there be a 20% drop in traffic ...
It's probably also relatively difficult to 'outsource' the role of a S/O, compared with a function such as catering, cleaning, etc. Besides, aircrew have already made significant contributions towards Qantas very healthy half year profit, by way of wage freezes etc, so I'd suggest that management may be looking elsewhere to minimise costs.
I won't stand here & defend Qantas management practices by any means, BUT... you've got to admit - the bottom line does look pretty healthy at the moment...
Just my thoughts.