The other members of their team or the village might have mixed reactions. Some might side with Sakura, understanding her point of view, while others might think she's being hasty or that they should try to preserve the relationship for the sake of the village's stability or their own friendship circle.
Naruto would be deeply saddened. He has always hoped for Sasuke and Sakura to be happy together. He might initially try to mediate and get them to work things out, believing that their relationship can be salvaged. He would remind them of the good times and how much they mean to each other.
One possible reason could be Sasuke's continued absence. He's often away on missions, leaving Sakura feeling lonely and neglected. In the story, this could build up over time until she decides she can't take it anymore and argues for divorce.
Kakashi, as their sensei, would be disappointed. He would hope that they could resolve their differences maturely. He might offer some advice based on his own experiences in relationships, but ultimately it would be up to Itachi and Sakura to decide whether to take it or not.
For their friends, it can be a huge shock. Naruto, for example, who has always been in the middle, trying to keep their relationship strong, might feel a sense of failure. Their other friends from the ninja teams might be divided in loyalty, some siding with Sasuke, some with Sakura. In the village, it could cause a scandal. The villagers might gossip and it could also affect the image of the Uchiha clan again, as Sasuke is part of it.
Sarada might be initially shocked and sad. She loves both her parents, and the divorce would be a huge blow to her. She could become withdrawn for a while, not wanting to talk to her friends about it.
Sakura may also try to find new friends and a support system. She could join a group of female ninja who have similar experiences or interests. They could encourage her to move on, and she might start to explore new hobbies or relationships, gradually getting over the divorce from Sasuke.
A fanfic could depict their separation and divorce in a very emotional way. For instance, Sakura might have found out some secrets about Sasuke that she couldn't accept. This led to a huge fight between them, and they separated. The divorce would then be a formal end to a relationship that had once held so much promise. It could show how their friends reacted to this news, some being supportive of Sakura's decision while others trying to get them back together.
Another reaction could be that Sakura tries to follow Sasuke. She believes that she can change his mind or that she can be of help to him. She might leave her own responsibilities behind for a while to chase after him, thinking that their bond is strong enough to overcome whatever is making Sasuke leave.
Sakura would probably be initially very angry. She has strong feelings for Sasuke, but kidnapping is a very extreme act. So she would likely fight back, using her medical ninjutsu skills and combat abilities to try and escape.
In this type of fanfic, it could be that external forces play a role. For example, there could be a new threat to the village that Sasuke feels he must face alone. He distances himself from Sakura to protect her, but she misinterprets it as him not loving her anymore. This misunderstanding leads to their separation. As for the divorce, it could be a way for them to finally move on from each other, even though deep down they still have some feelings left.