After watching Balance of the Force and the scene breakdowns, I do think I understand a little better where Rian was coming from in his take on Luke. That the last of the Jedi would intentionally isolate himself in order to make way for a new source of light-side users is something I could get behind.
But.
Always that but.
I didn’t get the impression that Luke had such a strategy in mind based on his interactions with Rey. If anything, during their time together he should have been pleased that his plan has worked so well, and that another powerful source of light has arisen in the galaxy to challenge Snoke and Kylo. If Luke had simply said in the Jedi Tree that the entire religion was fatally flawed, they could have gotten past their antagonism and into a more interesting and rewarding track. Luke could have realized what Rey wanted and said ‘I won’t teach you the Jedi ways, but I can be a mentor and a friend.’ Then when Rey dives into her dark interludes with Kylo the inevitable fallout would be sharper for her growing friendship with the former Jedi.