I wouldn't trust that site. George Lucas is the only authority on the subject, and I read the Episode 7-9 summaries and if you ask me, it sounds very woolly. If Anakin Skywalker restored balance to the Force by crossing back to the Light Side, why the hell are the Dark Jedi becoming such a threat? Plus, clones are NOT able to use the Force in any way, shape or form. If they do, it drives them mad. And the ending to Episode IX, setting off a Black Hole Superweapon has four main fundamental errors:
1) The Sith cult started on Korriban, not the system listed.
2) Only stars can become black holes, not planets. And if a black hole the size of that system was created, it would destroy a fair part of the galaxy.
3) It would be very un-Jedi to launch an offensive attack as described. If they did that, they would all touch the Dark Side and many would take the place of the enemy they had just vanquished.
4) The Dark Side originates through fear, anger, hate, mistrust, aggression and negative feelings. It might have been discovered on a planet, but that planet is not the source of the Dark Side.