The theme they picked (Yes! A real, actual theme!) was the dangers of taking our relationships for granted. I don't relate to it super well, because my parents were awful, but I liked the direction for Naruto. The scenes with his folks were excellent. The bits they allowed Sakura to have with her parents were nice, too.
Sakura gets the short end of the stick, as expected. Despite participating in the isekai plot as much as Naruto, it felt like she had far fewer scenes. That was a shame because it didn't have her engage much with the loneliness without her parents that we would expect to see. But it was there. I would have preferred that she actively confront the mirror world's Sasuke over his womanizing, but that would be a dangerous sort of scene that I wouldn't necessarily trust the Naruto team to pull off well without being misogynistic. I mean, the scene at the beginning, after the movie had established that Naruto would be extra emo about his dead parents for the duration of this, where Sakura said "sometimes I wish I didn't have parents." It read to me like they thought Sakura was a thoughtless person, especially when she escalated it to "Why are you even here? If Sasuke was here..." Because. Like. Damn. I was laughing for the wrong reasons.
The movie's shortcomings are that it sidelined most of the cast to focus on Naruto, even if it did so better than any of the other movies by being an isekai. It could be argued that the scenes we got with the rest of the cast were "enough" to play out the mirror world joke. I would have still preferred that they be the ones to come to Naruto and Sakura's aid rather than the series' villains. But having the villains turn up as good guys in the mirror world was valid, too.
I also wasn't a fan of forcing the climax of the movie to escalate so far afield of the theme. It was an excuse to have two tailed-beast hosts fight to the death, and it was unnecessary. The fight itself was fine, but I didn't think it meant anything. If anything, they should have had the final conflict be between Naruto and his parents—not necessarily a fight—so it would be an extension of his arc about learning to accept their love.
The inciting incident, where the Leaf Village characters' parents all write letters of recommendation to promote their children to jonin was perfunctory and weird, unnecessary nepotism that made no sense. But the movie got rid of that plot in less than a second because it was just an excuse anyway. Fair dinkum.
In 2012, they finally decided that a Naruto movie didn't have to be just an excuse plot. My expectations for the rest of the series has been suitably raised, and that rules.
