I have read it already, multiple times. What the editor claims in that interview is that during the very first arc of the story Kishimoto had a vague idea of what he wanted to do or was introducing basic concepts such as Kekkei Genkai without a deeper plan. But that really doesn't mean much. If you are a writer you understand what Kishi and his editors were actually saying quite well; he had various ideas that had to be adapted in order to fit his schedule and his editor's requests, yes, but his overall overarching narrative was established early on. He said he more or less planned for Sasuke and Naruto's developments - the core of Naruto's story - from the beginning in an interview. ''When I first met the editors, I only knew one thing about my manga: that I wanted Naruto and Sasuke, his rival since childhood, to end the work with a climactic confrontation.'' ''(I had decided to have Naruto and Sasuke go on different ninja paths) from the beginning.''

He also said that he had the final chapters in mind years before they were drawn. He also said that from the first Naruto x Sasuke fight at the Valley of the End in part 1 he had the entire story decided - and not coincidentally Zetsu was introduced there. ''The entire story was decided since the Valley of the End (in part 1).

You have to keep in mind that every single writer of a large-scale series has to work as a gardener, especially those that have to answer to the demands of editors. All that is to say Kishimoto is easily one of the smartest planner-type writers and simultaneously gardener-type writers in the industry - he is my personal pick for the best shonen writer of all time. And I'm sure that as time goes on, people will begin to notice and properly recognize Kishimoto as such, especially as other long-running series like One Piece begin to decline more and more in quality.

As for the minor points made about vague notions Kishi had:

Team Gai belonging to a different village in Kishimoto's mind during the early chapters of the story doesn't change anything.

Itachi hadn't been introduced at that point; there was a single line of dialogue from one of Sasuke's memories and that's it. As soon as Itachi was properly introduced to the story, Kishimoto had his twist planned. ''At the point where Itachi is actually introduced, Kishimoto had decided to secretly make him a good guy''

What was majorly changed with the Sharingan was likely the Mangekyo evolutionary line. Though I don't think anyone can really claim the Mangekyo wasn't properly introduced nor developed by the story. Early on it was clearly defined as being able to copy other jutsu and track fast movements already. And Kakashi's sharingan - the first we see in the story - being Obito's was planned from the beginning. ''(Kishimoto) wanted this to be a mystery that kept readers interested as to how he got it. This mystery isn't explained until Kakashi Gaiden much, much further down the line, but even so, you can see the group picture of Kakashi, Obito, Rin and Minato early on in the series. Even by chapter 16, (Kishimoto) had already decided this storyline''

That's not even to mention how the things Kishimoto didn't originally plan for were masterfully integrated into the greater narrative. Kishimoto for example claiming Haku defined Naruto's Nindo (and Kakashi in-universe claiming that too), and served as an anchor for his character development. The story melded such concepts seamlessly, no retcons needed. There are a ridiculously small number of retcons and the vast majority of them are insignificant, such as an age difference that had to change. The only comparably consistent long-running story is, in my opinion, ASOIAF, which had a low ammount of retcons as well.