ترجمة لمقابلة سابقة لكيشي ( للقضاء على نظرية أن كيشي اختار الناروساكو ثم غير رأيه)
1) Kishimoto did not change his mind. In order to change his mind, he would have had to deviate from the original idea. Kishimoto did not do that. NaruHina has always been the endgame pairing, and that’s what he went with.

First interview:

かなり前からヒナタで決めていました。
“I decided to go with Hinata [to be with Naruto] from quite a while ago”

Second interview:

ナルトがヒナタと一緒になることは結構早い段階で決めていましたね。
“Naruto ending up with Hinata was decided on in the very early stages of the story”
He outright says that NaruHina has been the plan from very early on.

2) No, Kishimoto never said he “really wanted” to pair Naruto and Sakura. He never said he wanted to at all. This is what he said:

サクラにしようかと迷った時期もあってのですが
“At one point/period of time, I thought about [considered] Sakura [for the role]”
takL translation is this: “There was a time when I wondered if I should pick Sakura (for the role)”
While NaruHina was chosen first and the original, at one point he only considered/thought about NaruSaku. It’s natural to wonder/explore different paths to take your story. However, he scrapped that idea after realizing how bad it was and stuck to his original plan (which was NaruHina).
Kishi explicitly says that there was a time when he WONDERED whether he should change Sakura’s feelings. He quickly dismissed that idea because as he said, it would make Sakura look bad to suddenly switch from Sasuke to Naruto (cue fake confession scene here), especially after he’s become a “hero”. He only “thought” about changing her feelings; it wasn’t materialized. Aka, this change of feelings never happened in the manga and everything he did with NaruSaku was done on purpose with the intention of misleading (which he says in his new interview himself; 「だからこそ、ナルトとサクラがくっつくかのようにミスリードさせるために、あえてサクラとナルトの母親であるクシナの動きを重ねるかのようなシーンを描いたりもしたんです」。He drew Sakura compared to that of Kushina, Naruto’s mother, in order to mislead.) and keeping people interested. He never intended on actually getting Naruto and Sakura together. The relationship was always platonic, as we’ve said for years.

OrganicDinosaur translation:

“I decided from pretty early on that Naruto and Hinata would be together. So I kept Naruto and Sakura close together in order to make it misleading. I even dared to describe and draw parallels between Sakura and Naruto’s mother, Kushina, in repetitive scenes, on purpose, to achieve that effect.”
And another thing:
なんだかんだでサスケに対して一途なんだと思います
“I think Sakura has always been devoted to/had her mind set on Sasuke”
Why would Kishi say this if he intended NaruSaku? No. Sakura’s feelings have never changed. She has always and will always love Sasuke.

3) Movie is not filler. It’s as canon as it can be and it’s 100% Kishimoto approved. The guidebook for the movie came out, and it is completely written by Kishimoto. It includes a two page NaruHina date that is set after The Last.

While I would have liked to see more NaruHina in the manga towards the end, that’s what this movie is for. To be taken as chapter 699.5.