That doesn't make much sense.
Depends on what you are trying to achieve.
Would make perfect sense to a actuary who will only be around for a few years and will collect on the way through if he could devise a scheme that would make the books look good.
Long term staff are a liability in a accounting sense, lots of sick leave, lots of holidays, massive super all of which is a liability in an accounting sense. If you can get rid of them it makes the bottom line look awesome.....
Then go about hiring a whole bunch of intakes on lower salaries and hope the wheels don't fall off, or there is a massive demand for your labour. Probably from Qantas's perspective they still believe everybody wants to work for them so they will never have that problem.
Airservices Australia is a classic example of all this. And about 10 years after they had some generous redundancy offers out there to get rid of the 'dead wood' they now have a staffing and experience crisis.
It has all been done before and it is all about financial engineering and creating an illusion that you are doing really well when in fact all you are doing are creating major problems for the next guy, but you are not paid to worry about that.