That makes me laugh, I'm not a fanboy of any individual character. Rinnegan is obviously a possible upgrade for Sasuke, not certain, but very possible. Again, if one thinks its a requirement for the DNA to be left dormant for 50-60 years to unlock Rinnegan, than they simply aren't thinking about Kishi's possible time-frame logically.
That simply won't happen.
Kishi has recently made Sasuke admit something that no one ever expected, that he wants to become Hokage. It is logical to assume, imo, that ultimately Naruto vs. Sasuke will determine the village's Kage. Resuming the story 30 years down the line just for their fight makes little sense to me, just my opinion though. Lastly, when it comes to their current jutsu, I doubt there is little more they can do to master all their techniques.