That's the media narrative that may have formed, but it wasn't accurate. They were an above average team defensively in 7 out of the 10 years prior to their cup win. In fact, the year they won the cup, was their worst year defensively. They were 29th in the league. They would not have won without great offensive performances by their stars in the playoffs.
Nobody said all that's necessary is "all offense", but no, the past 4 years did not prove that. It usually takes being very good to elite in at least 2 of offense, defense, and goaltending. The whole "defense is more important" narrative is baseless, and everything actually suggests it is the least important of the three. Our defense is improved, and that's a great thing, and will help us compete, but our situation does not support the narrative that was originally being claimed by the individual I replied to.