Well Sasuke went to Orochimaru out of his thirst for revenge. Assuming you're asking what if Sasuke never wanted revenge, he would have followed Kakashi's advice and gotten over it. He would have opened his eyes, see he had people who cared about him, accepted them as his friends/comrades, become a member of ANBU by now and be making something with his life.
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If Itachi told Sasuke the truth but still left the village, Sasuke may still have held a grudge for the Konoha elders. To be honest I think it'd screw Sasuke's mind up more for Itachi to tell him that. Think about it, how would you feel if your brother told you he was forced to kill your parents and get exiled? It's better that Itachi lied to him about that