Personally, I think the "youngest team in the playoffs" line is a bit overstated, because of how players were actually utilized and where the NYR relied on for production - specifically among the forwards. Miller-Fox-Igor absolutely fit the bill of a young elite core that should provide optimism for the future.
The forward group, specifically the forwards that are given the majority of ice time including PP time...not so much. All you brought up was what those players did THIS run. I am talking about the run after this one, and then the run after that. I don't know how you win a Cup today without an elite forward group and I'm not convinced this wasn't the peak for the NYR forward group due to impact-weighted age and cap commitments.
My anxiety is based on observing that the best teams in the league over the last 15 years or so have had a few things in common.
Most notably a homegrown core that they keep together for as long as possible to provide as many “kicks at the cans” as possible.
This makes sense because in the NHL, in any one given year due to injuries, puck luck, refs, etc. winning the Cup is a crapshoot.
Caps, Blues, Tampa, Avs cores were in place for years before they won a Cup to varying degrees.
But they built a core around their young talent, developed and added to it over a long period of time, and then reaped the rewards of this process.
The NYR are constantly attempting to cheat this process in various ways with predictable results. Building around short windows because all of your cap space is tied up on veterans right at the exact peak of their careers or slightly past it is not a sustainable approach to team building.
The lessons for successful teams are so clear but it emphasizes that at the end of the day the NYR are an entertainment product, nothing more to it than that.