Once Madara and/or Kaguya are defeated, TNJ’d or whatever, I believe the final conflict between Naruto and Sasuke will be over what will become of chakra. Throughout the manga, Sasuke has sought to resolve his issues by directly eliminating the source of said issues. At first it was Itachi who killed the Uchiha, then the elders/Danzo (after learning Itachi’s truth), Konoha, and finally Naruto.
This was before he was changed by his meeting with Itachi after which he went to seek out the truth about Shinobi, and the village system. These answers were provided by the Edo-Hokages making Sasuke choose to protect the Leaf, as well as want to become Hokage. In this case, he wanted to get rid of the flawed village system, hence his “burn it down” comment. After meeting the Sage, as well as learning about Black Zetsu’s manipulation of history, he likely views Kaguya (her power) as the source of all problems.
When all is said and done (Madara/Kaguya/BZ defeated), everyone will need to be released from IT. However, the massive quantity of chakra that was taken will likely prevent those people from continuing to be Shinobi. I think that the chakra left over after Kaguya’s defeat will be the point of controversy between Naruto and Sasuke. Naruto will want to re-disperse the chakra back to the people (as Hagoromo did), while Sasuke will want to keep it for himself, or possibly permanently seal that chakra away as to prevent another Madara/Kaguya.
Once again the transmigrants of Indra and Ashura would battle, though this time will be different (BZ’s meddling with the transmigrants would be over).This time Naruto will be able to successfully change Sasuke. I believe the battle would most likely take place before the IT is released and is likely to be located at the VoTE for symbolic purposes. By this time, Naruto may have regained Yang-Kurama, and Sasuke may have a second Rinnegan or an evolved Rinnegan (6T—9T).
Naruto and Sasuke would be evenly matched for most of the fight. However, their connection via the opposing forces of Yin/Yang will allow them to feel each other’s emotions throughout the battle. Naruto will begin to remember all those who helped him along as a Shinobi (Haku/Zabuza/Gaara/Kakashi/Hiruzen/Jiraiya/etc.) Eventually, as so many others before him, Sasuke will begin to be changed by Naruto. So for the most part, I agree with your ending.
Orochimaru's character will also have to be resolved in the ending. Many people will joke about Orochimaru having pedophilic dreams within the IT. However, I think he will dream about the thing he has always desired most: his parents. This way, the IT will act as a means to change Orochimaru's character for the better, and we will get to learn of Orochimaru's true motives.
Also whatever pairings happen will be shown in the end, but that's a thread
not for another time
Sorry for the Wall of Text U_U