It's good seeing so many people writing Boston off, will be nice for once to have lowered expectations. Just the opposite for teams like Ottawa and Buffalo, we will see how they respond to greatly heightened expectations, not an easy task for starved fan bases. The Bruins will be a playoff team, the best goaltending in the NHL, a top 5 defense with 2 legit #1's in McAvoy and Lindholm pretty well assures that. There is also a culture of winning and proven coaching which both the Sabres and Sens don't have.
Lots of flawed arguments here. "Best goaltending in the NHL" is not exactly a good thing, especially when that's only been the case for one season. It just means Boston overperformed last season. Goaltending is highly variable from season to season. You're in for a surprise if you think Ullmark is going to repeat his performance.
Boston has some good defenders, but defense is a team effort. Losing the greatest defensive forward of all time is going to be a huge blow to Boston's defense.
I'm also not exactly sure how "starved fanbases" has anything to do with this. Fans are not the ones playing on the ice. Both Ottawa and Buffalo played with greater expectations last season and played important games down the stretch. This is a non-factor.
Boston MASSIVELY outperformed what the metrics said they should have done:
That combined with the loss of many good players, a regression in goaltending, the big improvement of other division teams, and the potential regression of key (older) Bruins players means that playoffs are far from a sure thing. They obviously can still make it, but it's not a lock.
Fans of the Kings, Blackhawks, Sharks, Penguins, Caps all said the same things you did until they finally failed to make the playoffs.