I just had a twisted thought. What if "evil Naruto" is really KB in disguise, as a start to Naruto's training?
This would be a way to push Naruto into exploring how he really feels.
(KB had time to talk to the other Leaf ninjas, so could have found out about recent public events in Naruto's life.)
No. How would Killer Bee know about the autographs?
I'd guess that every Leaf villager would have gossiped about the autographs, which was done in the very public Ramen bar. So if KB asked for information about Naruto, that is something they would have mentioned.
I agree that it has little/no chance of happening, just an "out there" alternative answer.
For the Waterfall of Truth / Evil Naruto:
Just because E-Naruto talks about resentment, doesn't necessarily mean that Naruto feels that way (although he probably does). The doppleganger might be how Naruto *could* have turned out, rather than being a suppressed side. E-Naruto might be exploring why Naruto doesn't feel that way, when it would be natural to be emo like Sasuke. That would be just as revealing about he thinks, as if he was trying to hide any anger he might be feeling.
(Since someone had the Captain America graphic, I remember an article talking about C.A. way back around issue 250. They were thinking about having C.A. run for President, but the writer (Roger Stern) said he wouldn't do that. So the editors suggested to make *that* the story: why wouldn't Captain America run for president? Could be the same for Naruto: why didn't he turn his back on the Leaf village?)