What are you guys talking about? Have you watched the fillers so much that you forgot about main events?
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"He also stood toe to toe for a while with Haku, an exceptionally dangerous ninja with extreme speed and dexterity. It was during this battle that Sasuke awakened the legacy of his clan, the Sharingan."
So, Sasuke didn't activate his Sharingan right after the Uchiha Massacre. He got it during his fight with Haku.