they could rekindle the flames of Sasuke vs Naruto if by destroying the old system he means the old kages too.
think about it, if once there done taking out the ten tails orochimaru and sasuke have no need for the old kages, since there trying to rewrite the system, they try to take the kages all sorts of match ups could happen
Orochimaru can't control the first but madara would probably step in at that time and they'd have their battle I can see it now
First hokage vs Madara (old rivals)
Orochimaru vs Tsunade (sannin)
Oonoki vs saru (old, third, kage fight)
second hokage vs mizukage (cause Mizukage needs a moment to shine)
Raikage vs Minato (old rivals in speed)
Garra vs ????
and of course Sasuke vs Naruto