First, I'd like to say that Sault College has indeed an excellent program. My youngest daughter is planning on attending the pilot course next year. My oldest son is also a pilot. He's flying for Cathay Pacific in Hong Kong. There are tremendous opportunities throughout the world. There is a major shortage looming, with the number of aircraft on order and the number of pilots in the pipeline.
Having said that, the main impetus for the upward movement of younger pilots is not older pilots retiring; it's the airline being healthy and expanding. To that aim, it makes little sense to squeeze out experienced pilots who could mentor these younger pilots. There is also, of course, this question: why discriminate against one age group for the benefit of the other? Surely, it should be a balance.
I know in my earlier years it was at least 13 years before a pilot could possibly hold a captain's position with Air Canada. We have pilots with Air Canada now who were direct-entry captains, on the smaller aircraft, albeit. So times do change.