Wooh, doozie of a chapter.

I couldn't quite tell if they were saying that the 4th was Naruto's father or not, it was kind of ambiguously implied, but not quite stated directly enough.

However Carnage's train of thought might not be that far off. The timing of revealing some of Naruto's family history can't be completely coincidental, especially since the series seems poised to finally reveal what happened with Itachi back in the day too. Seems like having both of their family histories will provide the flashbacks during the action sequences for the upcoming battles.