I'm going to leave this here since it seems as good a place as any to put it....
I don't understand this idea that Karlsson was a bad teammate and was selfish. The truth is that nobody but the guys in the organization know for sure, but just from everything we've seen and heard, it doesn't add up in my view.
He risked his recovery in 2013 to come back from a torn achilles to help the team in the playoffs, and even returned in the regular season to help them get there. In 2017 he came back to help them get to the playoffs, and of course he was playing with a fractured foot and played the best hockey of his life that spring. He showed he was gritty and tough as well as being ultra-talented. The handshake line after being eliminated by Pittsburgh doesn't show a person that has a big ego or isn't anything other than a very classy individual.
And then there's what has been said about him. Right from day one, Boucher praised his professionalism and his work ethic. Dorion said "on the 8th day God created Erik Karlsson." Borowiecki said Erik helped him with stuff in his personal life. Chabot, as a rookie, praised him as a mentor.
Now, as far as his captainship, that may be a different story. But there are many ways to lead and I'm sure he wasn't a "rah rah" kind of guy so much as a lead by example on the ice kind of guy. I remember Phaneuf said in an interview after the 3rd period in Game 2 against Boston, after they came back from two down, that after the 2nd period there wasn't much said, because everyone knew what had to be done. Those type of expectations would have been set by all the leaders (Andy, Methot, Turris, Ryan, Stone, Phaneuf, MacArthur), and EK as captain would have been at the forefront of that.
I don't buy the argument that there was a rift because he had more leeway from Boucher because why wouldn't he? You're going to let Ben Harpur or Cody Ceci try to do the same things that he can? Obviously it was a rough season for Erik (at both ends) with the exception of the last 20 or so games, but it was a rough season for everyone but Stone and Dzingel. Everybody was bad in the defensive zone. I think Erik was very disappointed in his performance and was frustrated that his body couldn't let him do more.
As for the recent discussions that the team looks happier during the preseason than they did last season, well, of course. The team was out of it by Christmas, so having three months left in the season with no meaningful games to play is not exactly a cheerful situation for a hockey team, especially one that had the season they had before. If the Sens are ranked 25th-31st by Christmas, let's see how happy things are. The youth will inject positive energy, but that can only do so much. Besides, the team was such a "team" in 16-17 despite the entire league claiming how boring the team was and how it was possible to have fun playing that style.
Last season went bad in a hurry after the Sweden trip, and it was a result of many things. The turmoil in the dressing room could have been for a number of different reasons that are more complicated than "Karlsson was a bad teammate and leader." I have a theory that some guys weren't happy that Phaneuf refused to be exposed in the expansion draft so they could protect Methot, even though no team was going to take Dion and his contract. Maybe some guys were unhappy that the "go-for-it" move brought in Duchene but removed Turris. I'm sure the EK trade deadline saga and the Hoffman-Karlsson controversy wasn't easy to deal with for the locker room but Karlsson's play the last month tells me he didn't check out mentally after February.
Anyways, all of this is to basically say that without a former teammate coming out and giving details of what the room was like and Erik's role in it, there's certainly a lot of evidence to the contrary that Erik was nothing less than a consummate professional during his time here. Perhaps some teammates had issues with him, perhaps not. But he became captain in the summer of 2014, and none of this stuff came out before now. I don't think any of his teammates minded when he was the best player in hockey the last 3 months of 14-15, or when he carried the team out of a bottom five finish in 15-16, or carried the team on one foot to within a goal of the Stanley Cup final.