When I see Nylander dangle at the blueline with no one behind him while a game is still within reach, lose the puck and have the other team score, then have him do the exact same thing in the next game with the same result after taking a completely unnecessary 4-minute high sticking penalty that resulted in another goal against, and Berube's response is not to sit him to teach him a lesson, but instead reward him by sending him out with Mitch & Auston just minutes later.
I've seen all I need to see.
I'm convinced at this point during his interview for the Leafs' coaching job Treliving suggested Berube be introduced to his new bosses. And seconds later AM, Marner and Willie walked into the room.
"Tough" guy Berube has been neutered by this organization. Just like Babcock and Keefe before him and he'll get the same result out of these guys as they did. Early playoff exits until this core is gone.
Like OP said, there is still a lot of time but the warning signs are all there. This is the same group and they'll never change.