If JJ decides to contradict Rian in everything the ST is going to be the messiest trilogy of all time, with TLJ contradicting TFA and IX contradicting TLJ.
I guess the twist this time around could be that unlike Vader, who told the truth, Kylo/Luke lied to Rey and she actually is Ben’s sister. That’s the reason Maz recognizes her eyes, why Kylo asks ‘what girl?’, why Luke says he’s only ever seen that raw power in one other force user, etc. Kylo lies to her bc he knows that if she knew he killed HER father, she’d never join him.
Contradicting TLJ in that way wouldn’t just be a simple flip-flop. It could be part of explaining some unexplained plot points.