The novelization had his last line be in Rey’s head after he dies: “Noones ever really gone.” Not only is it a nice callback to Luke, but it also explains why Rey suddenly looks happy as she’s flying away in her X-wing.
Too bad he never said that anywhere.
It would be pretty easy to include “Rey, you’re not alone. You’ve become what you were meant to be.” using quotes from the hand touch and throne room scenes in TLJ.
Edit: Although that quote may be better to include in the Jedi voices section.