Joseki wrote:This makes sense if you consider the ending.
The entire structure of Shin makes complete sense if start from the idea that the movie itself exists so that Anno could completely close with Eva and the ending has to reflect that.
If Anno (and his desire is translated by the character Shinji Ikari) has to leave behind "Eva", then he needs to show Shinji leaving Eva behind, and the ending does that. To have that ending, Shinji needs to have all of his relationship be closed very definitely, and by having Shinji and Asuka talk only
after the plot has put both of them in a situation of no return their confessions are perfectly set up to express finality.
Alternatevely if Asuka came forward in part A, Shinji and Asuka both would have had to rediscuss their feelings later in the movie.
That make sense. Although because of that I feel that Shin is not the end of Shinji Ikari's story, but Hideaki Anno saying his farewell to the franchise, and while the movie was going to have of the latter (after all, Evangelion is and always was his most personal creation), it cannibalized the former. And the epilogue taking place in an Ube digitally modified to look like the one from Anno's childhood doesn't help me thinking otherwise.
Which lead to Shin where Shinji seemingly cut all the ties he made during his journey: he doesn't try to get close to Kensuke and Toji again (because they have their own adult life), doesn't try to get close to Asuka despite both living in the same place for whatever long they stayed in Village-3, barely talks to Misato and only to go to the final battle (where there isn't time to say much between them), and in the end decides that Rei should live away from him (thus preventing him from living with the Suzuharas), decides that Kaworu should live away from him (thus preventing him from going to live with Misato, btw did someone thought to ask her if she was okay with having Kaworu living with her instead of Shinji?) and decided that Asuka should live away from him. (thus preventing him from living with Kensuke)
Under that light, Mari being at his side in the epilogue is less a question of shipping or mentorship but more a way to avoid the ending to be depressing for Shinji, because at this point he has
no one else left in his life.As for Asuka coming forward to him in Part A, that wouldn't mean that she would spill the beans about the full extend of her feelings, the same way that Misato didn't immediately told Shinji why she was fighting the Angels and what they were protecting in Jo, or that Rei didn't came forward about her feelings immediately in Ha.
But have at least one first step, there are a ton of things that they could talk about and with no one else in Village-3: the true extend of Asuka's changes due to the 9th Angel (so e could realize with his own eyes exactly what he did to her), what's this curse of Eva that afflict them (especially since it's heavily implied that Shinji will be fully affected too), why Shinji didn't listened to her when she told him to stop in Lilith's Chamber (which could also serve to talk a little about Kaworu, I mean he's the dude that stopped N3I and commanded NERV for a time, they
must have things to say about him!), maybe a couple of questions about what happened and how things were during those past 14 years... that would contribute to the theme of Shinji gaining maturity, in that he tries to understand what happened to take the full extend of what he did so he can face the consequences instead of coming to an immediate conclusion and sticking to it no matter what.
And of course, the big question from Asuka about why she wanted to punch him won't happen there, because she felt that he wasn't ready yet (or that she fears the answer), that'll be for their final talk in the Wunder, as a way to seal the fact that yes, he's not the brat that he was before.