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 She could become withdrawn for a while, not wanting to talk to her friends about it.
Itachi would probably be very calm and composed. He might see Sarada as a symbol of the new generation of ninjas in the village. He could be gentle with her, perhaps sensing her potential and her desire to grow as a ninja.
Sakura would be heartbroken. She'd likely spend hours upon hours by Naruto's side, trying to jog his memory with stories of their adventures together. She might even get a bit overbearing in her attempts. Sasuke, who has his own complex relationship with Naruto, would be conflicted. He'd see Naruto's forgetfulness as a sign of weakness at first but then realize the importance of their bond. Kakashi, being the experienced leader, would start by observing Naruto carefully to see exactly how much he has forgotten and then start a systematic process of helping him remember.
Sasuke would likely be devastated. Despite their past differences, Naruto was his rival and in a way, his closest friend. He might go into a deep state of regret and isolation. Sakura would be heart - broken. She loved Naruto, and his death would be a huge blow to her. She might become more withdrawn and focus all her energy on her medical ninjutsu. Kakashi would be filled with a sense of failure. He was Naruto's teacher, and he would feel responsible for not being able to protect him.
Sasuke might initially be indifferent on the surface, but deep down he would feel a sense of loss. He has always had a rivalry with Naruto, and Naruto's departure would mean an end to that dynamic. Sakura would be devastated. She has grown to care about Naruto as a friend and teammate, and his leaving would leave a big hole in the team.
Naruto would probably be extremely happy and excited. He has always been close to Sakura, and seeing her become a mother would be a big moment for him. He might be there to support her during the birth, bringing some of his positive energy to the situation.
The ninja world would likely be filled with a mix of reactions. Some would see it as a positive sign of unity between different clans. Others might be worried about the power the baby could potentially have. There could be those who would try to use the baby for their own political or power - hungry motives.
Sasuke would likely be initially shocked. He's a man who has been through a lot and is used to a life of solitude and danger. But then, a sense of protectiveness would kick in. He'd become more vigilant about the safety of Sakura and their unborn child. He might also start to think about how to be a better father than his own was, in some ways, trying to break the cycle of his family's past.
They might be overjoyed. Since Sarada is part of their family, they would likely welcome her with open arms and big smiles. They could be very proud of how far she has come in her ninja training.