Why should Cathay pay for ten pilots to fly Townsville - Sydney return on QF/DJ ? They may only be interested in going to the next stage with four or five of them. Quite reasonable to expect applicants to get to Sydney at their own cost for the initial interview, and then to the nearest port served by CX if invited to HKG. Should CX give them a new suit as well ?
Standby tickets are no good for interviews. The panel run to a schedule and it may not be easy to get the chief pilot/training manager and human resources all together at once. Simulator time at $100s per hour needs to be allocated and hotels booked. If both parties are interested in a long term commitment to each other then it's worth a confirmed ticket.