More or less. A 64 year old max scale pilot costs the company more than a new hire in pretty much every way. Pay, vacation, sick time, health insurance all cost more for the older pilot. On the other hand the 64 year old pilot isn't being replaced by a new hire, he's being replaced by a 60 year old pilot who is also on max scale and who also cost the company more than the new hire in every way.

When a pilot at the top of the scale retires it starts a chain of (training) events. In reality, the new hire is replacing another first officer but the demographics are such that the new hire still costs considerably less than the guy he is replacing.

I'd guess that when you factor everything in from the savings of hiring a younger employee to the costs of training associated with it, there is a marginal savings. The real savings comes from growing the pilot group. Delta has hired over 1,000 straight growth pilots entirely on the narrow-body side of the company. There isn't nearly the training churn for growth new-hire pilots and each new hire lowers the average pilot cost.