Naruto would probably be really angry at first. He's a free - spirited person who doesn't like being forced into things. So he'd likely try to fight back right away, yelling at Sasuke about what he's doing.
At first, Naruto would likely be very confused and hurt. He has always craved family love and acceptance, so this sudden turn would be a huge blow. He might try to plead with his family, asking them to believe him and give him a chance to explain.
Sasuke might also be angry. Angry at the situation, angry at whoever or whatever caused Naruto's amnesia. His anger could fuel his determination to find a cure. He would push himself and Naruto harder in training, hoping that it would jog Naruto's memory, all while trying to hide his true feelings of worry and fear for Naruto's well - being.
The ninja community's reaction would be quite mixed. Some, like Naruto's close friends such as Shikamaru and Kakashi, would be supportive. They would likely offer their protection and assistance to Naruto during his pregnancy. However, there would also be those who are more traditional and might view Naruto's pregnancy as a weakness or something that goes against the norms of the ninja world. They could try to isolate Naruto or even oppose Sasuke's relationship with him because of it.
Shikamaru, being the laid - back yet perceptive friend, would probably think that Naruto has a plan. He would be concerned but also understand that Naruto is not one to make hasty decisions without a good reason. He might keep an eye on Naruto's family in his absence and hope that Naruto will return safely one day.
On the other hand, Sasuke could be worried. He may think that Naruto is in some kind of trouble or danger. Given their history and the care they have for each other in the SasuNaru dynamic, Sasuke's concern could lead him to be more protective. He might start investigating the situation on his own to figure out why Naruto is hiding his face and ensure his safety.
He could feel a sense of guilt. Sasuke might think that his actions or their relationship issues pushed Naruto to leave. He may then set out to find Naruto, not only to bring him back but also to resolve their long - standing issues. For example, if there were unspoken words or unresolved fights between them, Sasuke would see this as an opportunity to set things right.
His father, Minato, could be a likely candidate in a really dark fanfiction. Maybe he was resurrected in an imperfect way and his mind was warped, causing him to turn on Naruto.
He might try to prove himself. Naruto could focus on becoming stronger and more successful as a ninja. By showing his family that he can achieve great things and that he's a good person, he hopes to change their minds. For example, he might take on difficult missions and complete them with excellence.
His friends would likely be shocked. Shikamaru, for example, would probably be disappointed in Sakura. He might try to comfort Naruto and tell him to think rationally. Choji might be angry on Naruto's behalf and want to confront Sakura. And Sasuke, if he's around, might have a complex reaction. He might feel a strange sense of satisfaction that Naruto is finally seeing Sakura's 'true' side, but also a bit of pity for Naruto.