(sorry to derail) I think it all kind of cements Luke as being the fulfilled hope to the Jedi. Yoda has insight, and can see the possibilities that Luke will turn like Vader did. But Yoda also said it’s hard to determine if the visions are showing what is going to happen or could happen. Even when Luke rushed to save his friends, Yoda thought he was vulnerable and wouldn’t be able to resist that temptation. Luke seemed to despise the evil, instead of being tempted by it. To see this evil man, claim that he was his father, just pushed Luke over the edge (pun intended). Luke would’ve rather dropped to his death than face that truth.
I always considered his letting go, and falling as a suicide attempt. Might’ve been the will of the force that caused him to be pulled into the ventilation system, or pure luck. I don’t think Luke had anything to do with it. That moment where he was rescued by the crew of the falcon, he seems to have slowly accepted the truth. Even speaking to Vader, and then Ben through the force. This was a major turning point for Luke.
He’s wiser by ROTJ, but still has his final test ahead of him, with Vader and the Emperor. Luke might’ve came close during the Jedi duel, but I think he realized what his rage was turning him to. The symbolism between his mechanical hand, and Vader’s now severed mechanical hand.