Based on what?
, so now Rey suddenly isn't going to be trained by Luke?, fact is, they pigeonholed themselves here with the sloppy writing and desperation to give the female character the big moment in the first installment.
Rey can easily get too cocky and get that work from a pissed off, non injured and fully trained Kylo Ren. And we have no idea how the training with Luke will work, they can easily end up like Luke and Yoda on ESB were Rey thinks she's ready when she's actually not and then gets beat by a more focused opponent.
Not saying that's gonna happen. But to act like everything is lost because they made Rey too OP and beat Kylo in the first movie is going overboard.
Specially because given the possible stories and connections between all the characters, a final showdown on Episode IX, were Rey has learned from her mistakes and Kylo has completely fallen to the Dark Side (and are 1-1 in their encounters) would make sense.