The Last OG is purely fictional. It was made up by the writers to offer viewers an engaging and imaginative story rather than being rooted in real events.
In Naruto future reaction fanfiction, characters might react to various things. For example, they could react to new jutsu developed in the future. They might be amazed at the power and creativity behind it. Maybe Naruto himself would be excited to see how the next generation has advanced the art of ninjutsu.
Well, without knowing the exact nature of the 'order of throne og glass novels', in many series, the order helps in understanding the character development. As the story progresses through the novels in order, we see how the characters grow, change, and interact with their changing environment. This could be similar for these novels too.
It's not a true story. 'The Last OG' is a creation of the writers' imagination. Tracy Morgan's role is fictional within the framework of the show's made-up plot.
Naruto would be devastated. He has always idolized his father, so being betrayed by him would shatter his world. At first, he might be in denial, not wanting to believe that Minato could do such a thing.
He might be really surprised. Some fanfictions could show him in situations he never thought of, like different kinds of friendships or battles. He'd probably be curious about how fans see him and his world.
Naruto could find some similarities between his own values and Batman's. Both are determined to protect their respective worlds. However, the storytelling style in Batman fanfiction might be a new concept for Naruto. He may enjoy the complex characters and the dark, gritty atmosphere often found in Batman stories, or he could be put off by it as it's so different from the more straightforward good - vs - evil in his own world.
Naruto is devastated. He feels a huge void in his heart. Jiraiya was the one who believed in him from the start, and his death makes Naruto question a lot of things. He might even start to doubt his own strength for a while.
There would likely be a lot of negative reactions. Fans of the Naruto series who love the original themes of friendship, heroism, and ninja values would be appalled. The Naruto fandom is quite large and protective of the original spirit of the show, so this kind of fanfic would be seen as a desecration of the characters and the world that has been created.