Firstly, Sasuke would be deeply hurt. He might see it as a sign of his own unworthiness. Naruto, who has always been empathetic, would try to make sure Sasuke doesn't go down a dark path again. As for Sakura, she would be starting a new chapter with Naruto. Their relationship would be under a lot of scrutiny. The village that once hoped for Sasuke and Sakura's union would now have to adjust to this new situation. And Naruto would have to be strong enough to protect Sakura from any threats that might come from Sasuke's side if he turns vengeful.
The dynamic would be turned upside down. Sasuke would likely become more of an outcast or a loner, feeling rejected. Naruto would be in a difficult position, having to balance his friendship with Sasuke and his new relationship with Sakura. Sakura would be the catalyst for this change, and she would have to face the consequences of her actions, like dealing with the villagers' opinions and the potential backlash from Sasuke's supporters.