They would be shocked at first. Minato would be filled with pride and joy seeing his son all grown up. Kakashi would respect Naruto's strength. Obito might be a bit envious of Naruto's popularity but also admire his spirit. Rin would be very friendly towards Naruto.
When Team Minato meets Hokage Naruto in a fanfiction, their reactions would depend on their individual personalities. Minato would be overjoyed and would immediately start asking Naruto about his achievements and how he has led the village. Kakashi would be his usual calm self but would show his admiration through his words and actions. Obito, who has had a difficult journey, might initially be hesitant but then would be inspired by Naruto. Rin would be the most excited, perhaps jumping up and down and saying how wonderful it is that Naruto is the Hokage. This encounter could also lead to a deeper understanding between them all and a strengthening of the bonds between generations.
They would be empathetic. Minato, as Naruto's father, would especially feel a deep sense of pain seeing his son struggle. He would want to reach out and comfort Naruto during his lonely times when the village shunned him because of the Nine - Tails.
Minato would likely be extremely shocked. Naruto is his son, and the idea of Naruto attacking him would be completely unexpected. He would probably try to talk to Naruto first, to find out what is wrong and why he is being attacked.
They would probably be shocked at first. After all, seeing a future version of someone they know is quite unexpected.
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.
Sakura would be extremely worried. She would probably try to gather the other members of Team 7, like Sasuke and Kakashi, to go after them. Sasuke might be a bit more hesitant at first, but his loyalty to Naruto would eventually make him join the search. Kakashi, on the other hand, would be more strategic. He would try to figure out Minato's motives first and then plan the rescue mission accordingly.
Minato might be intrigued. He would be interested in seeing how the fans expand on Naruto's journey. Kushina would be delighted, seeing her son as the center of so many different tales.
Minato would react with concern and a sense of responsibility. He'd try to figure out the root of the problem. Kakashi would be reserved but still show empathy. Obito would be more upfront and vocal about his desire to help. Rin would be very gentle and motherly. For example, Minato might ask the reader about her family or dreams that have been shattered. Kakashi could share his thoughts on how he coped when he felt lost. Obito might offer to take the reader on adventures to show her the good in the world, and Rin would make sure she has something to eat and a place to rest.
Naruto would likely be extremely confused at first. He has always idolized his father, and to have Minato do such a thing would shatter his perception. He'd probably try to talk to Minato, ask him why he's doing it.
Naruto might initially be very confused and hurt. He loves his father and the village, so being banished would be a huge shock to him.