I mean sure, the Sedins are at the point in their careers where they're going to be "in decline". That is to be expected. I don't think anyone is expecting them to suddenly become 110pt+ players and win some more scoring titles again.
But i do really believe that last year was an aberration. An outlier year that doesn't/won't fit the "trend". It sounds like "excuse making", but that nightmarishly ineffective Tortorella system ran so completely counter to what the Sedins do well as players, that the impact can't be understated.
The Sedins are slow, cerebral, puck possession players who thrive on cycling the puck around and controlling the play in the offensive end until the opponent cries uncle. They benefit more than anything else from a system that provides the following:
1)aggressive puck movement from their own end where they can "cheat" a bit to negate their speed disadvantage.
2)the freedom to control the puck, spend a great deal of time with the puck on their sticks without taking a shot, enter the offensive zone with control of the puck.
3)offensive zone starts and prime offensive opportunities.
So what did Tortorella provide them with? A system that emphasized literally the complete opposite of that:
1)almost no puck movement from the back end, no transition, forwards collapsing deep down below the hashmarks in their own zone and having to lug the puck out of the zone themselves (the Sedins are not good at lugging the puck out of their own zone and through the neutral zone with defenders ahead of them because they are not great skaters).
2)shots shots shots, take a shot always (the Sedins entire game is built around an emphasis on holding the puck [sometimes for an inordinate amount of time] until they can generate higher percentage shooting opportunity).
3)top players playing the toughest minutes, a "power on power" approach (the Sedins may break even in "tough minutes" on the advanced stats sheet, but it's pretty clear that they feast on going up against less offensively gifted defensive lines, and doing so with a high degree of offensive zone starts to negate their limited transition savvy).
4)as a combination of #1+2, Tortorella's system emphasizing "shots" and a "dump and chase" approach, along with the fact that forwards were often "breaking out" from deep in their own defensive zone, lugging the puck up ice on an equal plane of advancement with their linemates, and with multiple defenders already set in front of them...it completely changed the way the Sedins play neutral zone hockey in a completely counterproductive way. Tortorella's brand of neutral zone hockey would've very nearly passed muster in the ancient "onside game" era of hockey where forward passes were not permitted. And the result of that system for the Sedins? Anyone else notice that it almost completely eliminated those "tic-tac-toe" neutral zone plays, and even the patented short area give-and-go zone entries from the Sedins' repertoire?
Add in a completely dysfunctional Powerplay where the Sedins have historically thrived, and you've got a recipe for massive regression from the Twins.
So yes, the Sedins are obviously "in decline", but last year was such a complete disaster that it really doesn't fit the "trend" of decline and it would be surprising if under a half-decent coach this coming season, the Sedins don't actually increase their production from last year.
