I had mixed feelings about this at first. I don't completely buy that Gen wanted to become Yuko, but when I thought about how many times the author did this kind of heel drop/turn, it seems feasible. I do take into consideration how these "truths" can seem true when spoken by the character, but later come to find out otherwise. When Reiji was in Tokyo with Gen, he said that Gen loved Yuko, and all the signs pointed to that made sense. Gen had that shocked pikachu face and said nothing to refute it.
I not buying Yuko dying. In addition to what I said last post, it is impossible she'd die off-screen, and without ever confronting Reiji. That would be super-anticlimatic. The author wants to burrow these characters in despair as far down as possible, and there's just no way that can happen if Reiji doesn't confront Yuko face to face at this point.
side note: I lol'd when Reiji saw Gen in his mother's clothes and was literally like "....Nope. Not dealing with this...",
. Hilarious.