Board Thread:Theories and Speculation/@comment-25139119-20150807165411/@comment-17623-20150808231522

Let's be real for a second though.

If Naruto had access to any of his Six Paths Sage Mode abilities, there wouldn't even be a plot for the Last as Naruto would have blown Tonrei to pieces. There wouldn't be a plot to Gaiden as the first time Naruto saw Shin Jr, he would have blown the kid to pieces. The plot of Boruto would not have been a thing, because Naruto would have blown the villains to pieces.

I don't know if the tailed beasts are required for Naruto's new cloak or what have you, but he was not going to keep his upgrades after the war. Sasuke needed Six Path upgrades to reach Naruto's level, and he still needed to suck extra chakra out of the tailed beasts to match him.