People he is suggesting that Sasuke will kill Naruto at the end of the manga. He is suggesting Sasuke wins in the end.
And as for my opinion on the matter, no Sasuke will not kill Naruto at the end. First its a Shounen manga, chances are we are going to get a fuzzy bunnies ending.
I think Kishi wants to make Naruto unforgettable by giving Naruto an epic and unpredictable ending!
Second, a major theme is that hard work can beat genius, if Sasuke wins than this theme is basically destroyed.
I will agree with you on this one but the overall storyline would be much better than following a theme IMO
Third Naruto said he wouldn't die until he becomes Hokage.
I'm doubting that Naruto will be a Hokage to begin with, because he doesn't need to be it anymore. He wanted the acknowledgement from the other villagers and he already got that.
Fourth having the hero die like that would send the wrong message to children.
Those children can go to hell. Naruto isn't exactly meant for children who want the hero to win, and I don't think Naruto dies, he will just lose the battle by a little tiny margin.