I don't believe that Qantas made a public announcement to keep call-centre folks happy (a significant portion of whom would be overseas anyway) - there's nothing in it for them.
On the call-centre side, they had 6 months to deal with the expected increase in workload. Like other pretty much every other industry, there should be business processes in place to deal with workload issues - not approving leave during busy periods, scheduling on more staff, overtime, hiring temp staff, etc. If they don't invest in customer service, then they deserve to be grilled. Yes, pity the poor sod who suffers as a result of cough management - I've been there, so I'm always conscious to blame the company and not the individual whenever I have a grievance - but that's no excuse for poor customer service.