And yet literally just one single year after that interview he approved the canon formation of the "New Sith Order" which is formed after the events of the OT complete with new "Darths" and everything:
I prefer the "once and for all" demise of the Sith in the Disney canon over the "they never go away Anakin's prophecy be damned" Lucas canon. If Anakin's involvement is necessary for you I'd think that you'd at least prefer him to be present during the final destruction of the Sith rather than him just killing one only to have an entire Order emerge years later.
George wasn't really shy about the fact that while the EU constituted canon, he didn't consider anything outside of his movies to be "official." He even flat-out said that even though the comics and novels had a returned Palpatine, none of it actually happened.
As far as I know, he was pretty clear about his personal insistence that Palpatine died, and that Vader ended the Sith. The EU was probably nothing more to him than money-making extensions of the brand in order to keep Lucasfilm going.
I personally never cared for the EU stories of a post-ROTJ SW. And later knowing that George didn't regard them as legit "truth" either made it all the easier to dismiss those stories. I was fine with the Palpatine "Contingency" as it was being put forward, but having Palpatine survive Vader/Anakin's actions crosses the line for me. I wouldn't be surprised if George saw TROS in a private screening and refused to go to the premiere because of his disapproval of it. And I wouldn't blame him.
Lastly, I don't think Anakin speaking to Rey at the end counts for much of anything since she heard all kinds of voices too, like Mace and Ahsoka. Those aren't Skywalkers, and having Anakin just be one of many disembodied voices telling Rey to get up so that she can accomplish something that Anakin apparently didn't is nowhere near good enough for me. The story value in Anakin destroying the Sith, and specifically the guy who ruined his life and family, is way too strong for me to let Disney override it with their anointing of Rey. GL would have to come out and endorse it all for me to even begin considering it canon.
Not sure I'm on board with that, at least from what we see in the movies there appears to be no difference whatsoever between the Sith and the 'Dark Side users' Snoke and Kylo. 'Sith' might aswell just be a club that Snoke and Kylo for some reason weren't invited into but really they're all doing the same thing. And what would it matter as far as The Force and the prophecy is concerned? Anyone can turn evil and use the Dark Side but only the ones in the Sith club are a problem that needs dealing with through a 'chosen one'? Why should that be? Meh.
Jedi and Sith are unique and distinct versions of light side and dark side Force users. The history of the Sith is its own thing; as is that of the Jedi. Not every light side user can ascend to being a Jedi; and not every dark side user is as dangerous as a Sith.
Imagine if broom boy starts using the Force to take care of Canto Bight thugs. That's a far cry from being a powerful Jedi who has mastered the Force. Or, since Finn is now Force sensitive, he'll need Rey to train him in the Jedi ways. Otherwise he'll just be a light-side Force user.
The same goes for the dark side. There are darksiders like Asajj Ventress who never ascended to being a true Sith. She (and others) draw from the dark side of the Force, but they're not Sith; just like Finn and broom boy draw from the light side but aren't Jedi.
Sith and Jedi are more than just amplified versions of their more "regular" counterparts. The Force works through them in ways that can affect galactic balance. And the Sith have the "Rule of Two." It's a concentration of power and knowledge reserved for a select few.
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