It could be that in Naruto's world, fanfiction isn't something that's common or known, so he's never been exposed to it and doesn't have the knowledge.
Maybe it's a powerful jutsu or curse that doesn't eliminate the characters outright but instead forces them to find a way to adapt and survive, leading to interesting plot twists.
It could mean that Draco, perhaps a character from a particular story (like in the Harry Potter universe), is not aware of the existence of fan - created fictional works based on the original story. He might be so caught up in his own world within the official narrative that he has no knowledge of the fan - made stories that fans write about him or his world.
Well, there could be various reasons. Maybe the writer wants to create a unique situation where Naruto is silent to add mystery. For example, if the fanfiction is set in a scenario where Naruto has lost his voice due to a curse or some kind of magic. It could also be that the author is focusing on other characters' reactions to Naruto's silence, which can bring out different aspects of their personalities.
It's important because it maintains the integrity of his character within the original story. If he knew about fanfiction, it would be like breaking the fourth wall and would seem out of place for his character who is supposed to exist solely within the original narrative.
Maybe Naruto just sees Sakura as a friend. He might have a different idea of his ideal partner and Sakura doesn't fit that. His feelings for her could be purely platonic.
Perhaps it implies that Naruto, as a character with strong beliefs and a sense of justice, wouldn't tolerate certain types of fanfiction. For example, if a fanfiction portrays him or his friends in a completely negative or immoral light that goes against the essence of the Naruto series, he wouldn't 'forgive' it. Fanfiction sometimes can go to extreme and inappropriate lengths, and this statement might be a reaction to that.