Yeah, Boston lost major pieces of their core. The Rangers have been much more of a WTF just happened sort of deal.
Honestly, I'm not so sure the Rangers struggles surprise me at all. Maybe it has been me being biased by my disdain for them and wanting them to fail, but I've thought for years that they really haven't built their team well at all to be top tier contenders year in year out, and it was just a matter of time before this collapse with the same core came.
They got a bunch of mercenaries specifically because those players wanted to be in NY and the Rags weren't going to pass up the opportunities to add them, not because they fit any type of established team culture or systems or deliberate team building plan. Panarin, Fox, Trouba. Panarin, similar to the Leafs' top guys, is not a playoff performer. Zibanejad overachieved for a while but never struck me as a true 1C for a playoff team, Kreider had some seriously unsustainable production as well.
Their drafting and development have been really quite bad for a while now, a large part of it being the accelerated rebuild by adding those mercenary guys -- I mean Kakko and Laf certainly have had their issues that are their fault, but the Rags did not really give them opportunities to develop or succeed.
They overpaid in assets for deadline trades (Kane, Tarasenko), overpaid guys like Trocheck for the short term benefit. Have had really poor leadership structures (largely due to the mercenary aspect IMO, but also not really giving coaches much leash due to overly high expectations).
The biggest thing though is a lot of their success with this core has been due to Igor playing out of his mind and having an elite powerplay. Their 5v5 scoring was never anything special, not terrible but not amazing, and their team defense really just has not been good at any point. Outside of Fox who I think is overrated defensively, they haven't had any standout defensive defensemen. As they found with never winning a cup with Henrik, relying on goaltending to win is incredibly unsustainable and not enough. And powerplays can go cold too and not be enough.
I'm not sure I expected the perfect storm of everything going wrong for them like it has the past few months or whatever, but none of it really surprises me, and I think they are in really rough shape going foward, as are the Bruins. Not much in the way of younger players or prospects that indicate a bright future. Bruins have none, Rags have Perreault maybe but still early to say how much of an impact he could have.
Igor playing elite again could certainly get them into the playoff races, and we know he's capable of it but I don't view them as contenders or big threats going forward.