One other forgotten thing is the lost decade has made the average age for regional pilots older. Between Flows and DGIs and CPPs, and off the street hires, there will be some 45-55 year olds being hired at mainlines, that will then be retiring in 10-20 years.
So the graphs you see with retirements per year starting to go down in 10-15 years really won’t be. The peek retirements per year could last for longer than the data is showing if a few 100 older pilots are hired each year at each legacy over the next 1-5 years.