Bamse01 - you obviously didn't read (or take in) what was said. Retraining from one type to another, under this scenario, would obviously be available to those that merited it. There would be no bonding (which would make tilii happy) and as it's a privilege and not a right it therefore becomes an incentive.
Recurrent training would of course be the airline's cost - though in other industries it is indeed the individual's responsibility to remain current in their speciality.
Read QAww's post on DHL/EAT and you'll see how it works.
Regardless of whether or not you think it's a good idea, I strongly suspect this is the way that things will go. Already you have many airlines requiring people to be type rated - or pay for their own ratings (Southwest and Ryanair are just two) and frankly there's not a lot wrong with that. To do otherwise would be like employing a programmer with Pascal skills and retraining when you need a C++ programmer!
The primary benefit to employees is that they are then free to move around as they please (without the constraints of bonding) and in order to keep the best people the airlines need to look after them. This would include good pay, lifestyle, promotion, and conversion on other types.
As I said before, it's a win-win situation.