The ending to Star Wars: The Force Awakens was changed at the last minute (relatively speaking), in order to avoid introducing a continuity error between director J.J. Abrams’ film and its followup, writer/director Rian Johnson’s The Last Jedi.
It sadly meant that Han and Luke didn’t get their emotional goodbye, but it has made Luke’s return all the more mysterious ahead of The Last Jedi.
Presumably leaving the sanctuary of his exile, The Last Jedi pits Luke as Rey’s unwilling trainer before he attempts to disband the Jedi Order forever.
Moreover, it seems like whatever the original ending to The Force Awakens was, it wasn’t a dramatic departure from the final version.