So then the question is... Does "Last Jedi" mean a paradigm shift, extinction...or both?
To me, it really feels like both. We know from some stuff in The Force Awakens' novelization that there's been emphasis on Kylo Ren's history of, "one foot in the dark one foot in the light" being something that held significance even though it didn't make it to that film, so I think that, along with Rebels exploring more of the in-between areas of the Force with The Bendu, Ahsoka, & Maul, I have a feeling that we're going to start to push into areas not touched by the more rigid extreme dogmatisms of the Jedi & Sith for the roles that Rey & Ben fill. By the same token, I think that Luke's sort of emphasis on that will make him properly the last Jedi (although it's worth noting that in plural it's still, "The Last Jedi"), and at some point we know he'll pass on that legacy properly to Rey in whatever form it takes.
(God, I really hope that after this film gives us what it gives us that Dave Filoni's next animation project is something related to Skywalker's Academy & the Knights of Ren, because he seems to love to take on the stories of the characters that are destined to be doomed – Ahsoka, Kanan & Ezra, etc).
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