I have my doubts on if that were the case; it's probably communication here. If Naruto had ended during the Pain Arc; it woulda been perfect. It WAS the perfect arc to end a series at. If Sasuke, Tobi, and all of that were handled before the Pain arc.. I could of seen it ending there.
But, since before part 2, Kakashi gaiden pretty much set up for where we are now. Kishi most likely had no plans on stopping at the Pein Arc.