Certainly, the trade between Weber and Subban remains one of the most significant in modern hockey, even though both players are theoretically retired (Weber awaits the end of his contract).
Undoubtedly, it's considered one of Marc Bergevin's best moves. Yes, Subban was highly regarded in Montreal, and his departure was a shock, but Shea brought the leadership the Canadiens needed.
This leadership is still evident today, as the current and future leaders, Nick Suzuki and Cole Caufield, have learned from him. And it must be admitted that for 23 and 24-year-olds, they are doing quite well.
Former Predators GM David Poile was asked to comment on the trade, and he was very candid. If given the chance, he probably wouldn't make the same trade again.
Certainly, the former #6 was highly respected wherever he went. Winning the Mark Messier Leadership Award, given to the greatest leader in the NHL, is no small feat, and he won it.