My humble take: If people want to say Reaves can set a tone from the fourth line and in the locker room, can give the star players a perception of protection, give some possible vengeance against a transgression (maybe at some point) and not be as awful as Howden was last year, I can concede that.
but....
Saying that Tom Wilson did what he did to Buch/Panarin because of the Rangers lack of grit and leadership and Wilson will absolutely never do that now that Reaves and co are here just doesn't hold much water with me. I'll say it a different way this time:
The same thing happened to the evidently "lacking in leadership and grit" Bruins a month earlier. The Blues went through the same thing (twice), the Pens went through the same thing (twice)...etc. ALL lacking in leadership and grit???
....or Tom Wilson does what he does to all those teams because that's who Tom Wilson is as a player. Just as Bryan Marchment, just as Steve Downie, just as Matt Cooke, etc, etc were before him.
Reaves was on the Knights when Wilson laid out Marchessault with that big hit in game 1 of SC finals (Vegas won that game). Wilson knew who Reaves was before that game. Didn't stop him. Vegas lost the next four games and the series. Reaves played in three of the games and then not in the last.
Reaves gave Wilson a receipt a year later in the 2nd game between the two teams. Felt really good. Didn't fundamentally change Wilson as a player though.