That's quite the reach. Hughes is 2 years younger than Matthews but the Devils are starting their 'Cup window' while the Leafs is over? Meier is older than Matthews and drafted in the same year as Marner.
Markstrom/Allen are 34, the oldest goalies on both teams. This same Devils core couldn't make the playoffs last season.
Definitely not over (not sure how you inferred that from "nearing the end"), but Toronto is certainly on the downside of that Cup window opening.
Will still have a few more cracks at it though and we've seen teams such as the Caps and Blues finally break through when most were ready to write them off, so I certainly wouldn't rule anything out.
You're also being very disingenuous as to why the Devils didn't make the playoffs last season - with injuries, goaltending and coaching all being big factors. This is a much different team than last year, so I'm not sure what that has to do with anything. Could also point out that this same core set a franchise record for points just two seasons ago and won a playoff round.
There's also a 3 year and 7 month gap between Hughes and Matthews.