Well, you can't keep the hermit angle for too long once someone's arrived to disrupt it. Ben hung out in his house for like 3 minutes lying to Luke, and then he was gone.
Rey shows up at the end of one movie. I'd imagine with the timeskip between the two movies (there's gonna be SOME semblance of a timeskip, I'm sure. Maybe not a year or two, but time will have passed) by the time we get back to that rock, they'll be more than ready to get off it and do some shit. There's not much drama in hanging out there with Luke in his self-imposed hermitude. It was never going to last all that long onscreen.
I don't know that he'll necessarily be happy and excited, though. It's still possible that Luke will have been fucked up to some extent by what happened at his old temple, and even being reunited with his daughter (if that's what she is) will only go so far towards healing whatever those wounds are.
But it seems that one of those "awright, lets go" type scenes might include Luke striding out of his little hovel looking more like "LUKE." It's simple, but it also immediately tells the audience that a change has occurred without having to actually use words.