For all cases, Sasuke is going to hurt Naruto, that much is true. As for the past, yes we know it was the system that lead to his clan being killed and despite how others wanted to find peace, they went that path which made Sasuke into the person he is. But the past he wants to erase, the tailed beasts are part of that past, so its reasonable to see that because of the picture of team 7, with Naruto's face getting slashed, he intends to remove Naruto from it too because he is part of that system which allowed the troubles and corruption of the world to grow. Naruto is doing things under the right ideals though while Sasuke is doing it all by force because of what he thinks is better so no one suffers the same fate as him. For all cases though, for Sasuke, we know these to be true:
-He is working primarily under Itachi's sacrifice so the village and his own do not go to waste cause of Madara's plan
-For now, the ordeal is an enemy of my enemy type situation, he is working with the allaince to stop Madara and Obito so he can still put his plan in action, remember no world means he cannot put his plan into action, he needs to help save the world so they can at least exist for the change to happen. Compared to Obito and Madara, the corrupt ninja system he wants to change is the lesser of the evils he sees, so he is helping the allaince for this obvious reason.
-Sasuke's plan involves changing the shinobi world, by means if he can be hokage or just force, however unlike Sasuke, Naruto knows the real reasons for it, espcially because of what Itachi told Naruto.
-Itachi is the key between Sasuke and Naruto's resolution, at a point in the future, Naruto will reveal what Itachi told him, possibly even what his own parents told him and how they made him the jinchurki of kurama yet he was able to become a better person despite being born in darkness, alone, and in tragedy.
-Orochimaru knows what Sasuke will do, "his new wind" obviously we know this can be an obvious clue to Naruto finally changing Sasuke for the better, hence Naruto is the wind to Sasuke's fire, turning the fires of negativity to positivity. Oroachimaru is unknown at this point but he is following Sasuke also most likely going to save Yamato (someone has to).
-Aside from the system Sasuke wants to change, he wants to erase the past, this can have several meanings, mainly like the curse of hate, it can relate to the system again, it can even be his own. I'm betting its the curse of hate and the system intertwined because of the system is what forced Itachi to become what he was and made Sasuke go his own path too. Not to mention the system focused on the power of the tailed beast so much, its what drove events like the Uchicha being discriminated and resorting to riot in the leaf if they got the chance. Because of obito, the leaf suspected the Uchiha of being responsible for the nine tails attack. Hell this suspicion against the Uchiha went so deep, Hiruzen's old rotten teammates thought Hiruzen was trying to give control of Kurama to Sasuke because of putting Naruto and Sasuke on the same team, rather when it was because they were assigned together (with Sakura) for other reasons, Kakashi was chosen to lead mainly so he could watch over Naruto and help Sasuke with his own Sharigan, Sakura would just become a better fighter under someone like him (this was the original intent).
-Whatever Sasuke's actions are, its negative and someone will be hurt. At this time he shows stubbornness and still the superiority aspect of doing things his way. Jugo and Sai found he had other plans, Sai does not trust him, Sakura surprised everyone by showing this too, she does not trust him but her fake smile shows how much it hurts her and she knows it can be bad. Harshirama was frustrated with Sasuke too during the let it burn event. Now with Sasuke saying he will defeat/kill Naruto, the picture of Naruto getting cut, obviously Sasuke can be easily making good on his promise to face Naruto first (from the land of iron events) If he wants to change it, this includes defeating Naruto. Whatever the case, Sasuke intends to harm Naruto after Madara and Jubbito are dealt with. Sasuke intends to harm Naruto no matter what, it is this situation that will most likely tie into Sakura not trusting Sasuke leading to a big reaction of how Naruto and Sakura will handle Sasuke's choice despite his choice to spare the village and honor Itachi's sacrifice. If anything, Sasuke is going to spare the village because of Itachi, however he is trying to change everything by force and going about change the wrong way, Itachi wanted something better but Sasuke is doing it all wrong because unlike Naruto he does not have the right ideals or knowledge of why, as Itachi told Naruto, one only becomes hokage because they are acknowledged, one does not become hokage to be acknowledged, Naruto's orginal thought for becoming hokage was wrong, he could have become it but no one would respect him, basically Naruto worked to get the respect he did so the people would have faith and care for him, not just become accepted due to a position. Its with these events Sasuke is doing it wrong.
Still I'm betting as more with Sasuke's cooperativeness is revealed, it will bring more revelation to the future conflict and ultimately development on Naruto and Sakura and that this could be the trigger for NaruSaku. With Sasuke's intent to harm Naruto being clear, its becoming more realistic to see how Sakura would react to see her best friend suffering or if she herself choses to stand fully against Sasuke when the time comes. Basically Sakura's movement from Sasuke to Naruto may start to finally be set in motion having begun at 635 and now more elements can come to build on it. God Narusaku is enjoyable for the joy, sadness, and drama, such a good pairing it hurts. Hope we get more humorous moments in the future like 631 or rather an upgrade of the 450 event, that would be nice. NaruSaku is still on track, things look very good for it.