There is only one reason Qantas and Virgin have established their own pipeline...and that’s to address a structural pilot supply problem.
If you were selected into the Qantas program you would be crazy to not accept it based on the above logic. There is no guarantees in any job, let alone at training stage. What Qantas has is several subsidiary airlines and that means jobs.
I know what ticket I’d want.
The better questions would be:
What are the experience and quality of instructors? Where are they coming from and why?
Is the course good value? If you live in Adelaide, is it worth moving?
So back to the top, there is a supply problem of pilots. Training with a Qantas ticket is unlikely to restrict future employment, but it might give you a leg up.