Just wondering...why did Minato say "I leave him to you" when he was talking to Sakura (about Naruto). Isn't that supposed to be a significant statement in Japanese culture? That whole interaction (and the 'she's my girlfriend' statement) was one of the things I took as a pretty big indicator of NS being the OTP. There is no way to twist it in favor of NH, it's pretty unequivocal in support of NS.
Anyway, another theory...maybe the movie was done by one group, and the manga was continued by Kishimoto, who knew it was giong to end NH but never cared to adjust the storyline. He just wrote what he wanted, continued with the NS/anti-SS vibe, then when it was time to end it, he just ended it. Wrote the last chapter and epilogue to be flattering to NH/SS and line up with the movie, and then it was peace out.
It was like a tv show being suddenly canceled. Except that Kishimoto knew the movie was coming. So I'm wondering if Kishimoto just wrote whatever he wanted, then slapped on a NH/SS ending.
And when they wrote about staying tuned for a "shocking ending" in the manga, I thought it meant that Sasuke was going to be Hokage. Silly me, thinking it was going to be about the plot. Instead the "shocking ending" had everything to do with the romance.