Yeah, sadly I only saw that statement as part of a discussion that was taking part on the tumblr NaruSaku tag. Just as Michi said, the nearest source I could find was Kishimoto asking us all to read chapter 700 to "understand" the movie.
If it does turn out that The Last movie will simply confirm NaruHina and SasuSaku as canon, and try to retcon 15 years of the manga, then a LOT of Naruto fans (not just NaruSaku) are going to be feeling very betrayed. You simply don't tell a story for 15 years, then give it a rushed and poorly written ending with random developments thrown in for cheap shock value.
Can you imagine JRR Tolkien ending Lord of the Rings that way? Frodo and Sam got blown up in the volcano, Gandalf disappeared into thin air, Legolas married Arwen, and Aragorn married Eowyn.
If Kishimoto and Shonen Jump have really decided to retcon Naruto, then a lot of fans are not going to be buying any more Naruto merchandise. Why would they, if the mangaka and publisher couldn't respect the story enough to give it a proper ending?
Of course, if this is all an elaborate marketing ploy to get everyone talking about the weird ending and deliver a further twist (like NaruHina/SasuSaku were NOT canon), then they'd be absolute bastards for putting all the fans through the emotional wringer...
Either way, I would have preferred a well-written ending that neatly tied up all the storylines, even if NaruSaku wasn't made canon. Nobody should "end" their story with a cheap marketing stunt.
Now this is a post I can get behind for sure! You rock, Smiter! And it's nice to see someone else thinking about this whole mess!