>>41151821He's right, though.
Regardless of whether or not SwSh exists, you can go back to the previous games and not have your experiences phased by them.
Conversely, if you watch TLJ, you cannot go back to the older movies without the lingering plot hole of "why don't they just send a suicidal light speed ship to blow up the Empire," you know that Luke's journey will take him to a retarded end where he doesn't even have the gall to fight in his last living battle. You know that Luke rekindling the Jedi Order is a mistake that leads to the First Order, causing his journey in Episode 5 to be meaningless.
None of that is a merit to SwSh, it just means TLJ is fucked beyond all repair.
