Sasuke knows what happened, but he wants to know why
I think it's pretty obvious what Sasuke wants Orochimaru to do, I think he wants to revive the Uchiha clan to figure out the details of what exactly led up to the Uchiha massacre. I mean if you think about it, what do we know about the Uchiha massacre so far?
-The Uchiha clan was treated "badly" so they plotted a revolt
-The elders took counter measures to this planned revolt by recruiting Itachi to massacre the clan in the middle of the night so that they could save the village
-Negotiations fell through between Hiruzen and the Uchiha clan
-Itachi and Tobi slaughtered the Uchiha clan.....
See, that's extremely vague, we really don't know WHY the Uchiha's planned a revolt except for that they were "treated badly". Sasuke probably wants to know exactly what led up the Uchiha clan wanting to do such a violent thing as revolt against Konoha. I mean the entire context of the conversation between Oro and Sasuke is about how Sasuke is unsure about taking revenge on Konoha. Remember Sasuke back at the Kage summit? Sasuke wasn't using his head and was recklessly trying to kill Danzo
Oro commented on how Sasuke changed for a reason, Sasuke wants to know WHY the Uchiha were planning a revolt so that he make his own decision whether or not to take revenge on all of Konoha, aka Sasuke just had a huge jump in his maturity level. So now Oro is probably taking Sasuke to his hideout to gather the materials to revive the clan
Of course that wouldn't really involve the scroll, so maybe the scroll is about how Tobi has the materials (aka eyes) to revive the Uchiha clan, and Oro and Taka going there to get the materials to revive them (Kabuto did know where the hideout was, so Oro probably knows too). This would also make things interesting with Nagato's other Rinnegan currently in Tobi's hideout, and that would explain why Suigetsu immediately thought of Sasuke when reading the scroll for the first time
There are two other groups of people that Oro could revive, but one is kinda random and the other one would be massive trolling on Kishi's part. Oro could revive the three elders who are presumably deceased from Hiruzen's generation, Kagami Uchiha, Torifu Akimichi, and Danzo Shimura, to find out about the entire history of Konoha, Madara, and Tobi, but I just don't think that Sasuke is that interested in all of Konoha's history, Madara, and Tobi atm. The scroll could also be how to revive souls out of the Reaper Death god, but that would be a massive troll move on Kishi's part by reviving people he clearly wanted to seal forever before
Those are the only three groups of people I could think of that would make any sense at all, with the Uchiha clan making the most sense. So what do you guys think?