The NHL, on average, is getting younger. In 2007-08, five teams (Anaheim, Calgary, Detroit, Carolina and Atlanta) had final rosters where the players' average age was 29 or older. In 2015-16, the current oldest team in the league is the Minnesota Wild, at 28.292 years, according to NHLNumbers.com.
Look around the league today, and several teams are not only getting solid contributions from first-year players, they are almost dependent on them for overall success. The Edmonton Oilers had problems when Connor McDavid was healthy, but they quickly sank back to the bottom of the Western Conference standings when the 19-year-old went down with a broken collarbone in early November.