The problem there is the extent to which early retirement reduces their pension. It may well be so much that they HAVE to get another job, rather than it being a 'only if I want to' situation. They would also be worse off than if they were made redundant, because of the lack of the redundancy pay, so they would get hit twice. There's also the question of whether or not company pension funds could afford the hit without drastically reducing pensions even further.
Those not in a company pension scheme would be better being laid off, too.