On a more positive note, it could inspire some young ninja to step up. They would see Naruto's departure as a challenge to prove themselves and fill the gap he left. His leaving could also make Konoha re - evaluate its relationship with its ninja and how to keep them satisfied and in the village.
Konoha would initially be in shock. Naruto is a hero to many in the village, and his sudden departure with Itachi, who was once considered a traitor, would cause a lot of unrest. The villagers might start to question the leadership of the village, wondering why Naruto left and if there was something they could have done to prevent it.
It could lead to political unrest in Konoha. There might be those who blame the village leadership for Naruto's departure. This could lead to power struggles as different factions try to take control and change the way the village is run. Some might demand more transparency and better treatment of their shinobi to prevent such a thing from happening again.
It could create a sense of unease and fear. Naruto is a very powerful ninja, and if he turns dark and leaves, the villagers would be worried about him coming back as an enemy. It might also lead to a decrease in morale among the ninjas who once considered Naruto a friend or ally.
Konoha's power structure could be affected. Naruto is one of the strongest shinobi in the village. Without him, the village might be more vulnerable to attacks from other villages or threats. They would need to quickly find ways to fill the gap in their defenses.
Perhaps he would journey to the Hidden Cloud Village. There he could meet new people and learn different techniques. He might also try to bridge the gap between Konoha and the Cloud Village, starting from outside Konoha's boundaries. This would be a way for him to still work towards peace on a larger scale, but away from the restrictions he felt in Konoha.
Sakura would be heartbroken. She has deep feelings for Naruto, and his sudden departure would make her feel abandoned. She might initially be angry at him for leaving without saying goodbye but would soon worry about his safety.
His friends would be worried. Sakura might be very concerned about his safety and feel sad that he left. She may also feel guilty if she thinks she could have done something to prevent his departure.
His relationships with his friends like Sasuke and Kakashi would also be affected. Sasuke might understand Naruto's decision on some level, having also left the village before. Kakashi, on the other hand, would be worried about Naruto. He might try to find him and bring him back. This could create some tension between Naruto and Kakashi as Naruto tries to assert his independence.
Perhaps he feels pressured in Konoha. Having a kid adds more responsibility, and he might think that leaving Konoha will give him the space he needs to grow as a father and a ninja without the constant eyes of the village on him. He could be seeking a place where he can train his kid in a different way, away from the traditional Konoha methods.
His ninja skills may develop in a different way. Instead of learning the traditional Konoha - style jutsu, he could be exposed to new and different forms of combat. This might make his fighting style more unique. Also, his view on the ninja world could change. He may start to question the values that Konoha has taught him and form his own set of beliefs.