What I think should have been Chewie's big moment about Han is a conversation with Luke in TLJ. Both men would feel responsible. Responsible for Han's death and letting Leia down. So them having a conversation about it would have really worked imo. When Luke goes up to the Falcon, instead of sneaking on, I would of had him have that conversation with Chewie, where they hash things out, and then Luke would ask his permission to board to the Falcon.
It amazes me how little Chewie is in TLJ, and more over, how little character he has. He is nothing but a plot device, that stands in the corner. Which sucks, as JJ clearly sets him up as Rey's big buddy, who is there to help her. It was more RotS more so then Empire, TFA or Solo Chewie.