There could be various reasons. Maybe the fanfiction's setting didn't provide opportunities for them to interact, or Sakura might have been in a different part of the story world when Itachi was making his mark.
It could be that Sakura's path never crossed with Itachi's in the fanfiction's plot. Or perhaps the author just didn't write about her knowing him for some creative reason.
Maybe she was focused on other things and didn't pay attention to Itachi's story.
Well, some fans might create such fanfiction because they think Naruto's relationship with Sakura was more of a friendship. They feel that Naruto had a deeper bond with other characters like Sasuke in a different way than a romantic love for Sakura.
This could lead to a very interesting fanfiction plot. Maybe Sakura is afraid to tell Sasuke at first. She might be worried about how he'll react, whether he's ready for a child or not.
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.
Maybe in the fanfiction, Naruto grew up in a very isolated or unloving environment, so he never experienced hugs.
Maybe because in the fanfiction, Naruto's upbringing and experiences didn't expose him to enough examples of love.
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 in that fanfiction, Naruto grew up in an isolated or deprived environment where such concepts weren't introduced to him.
In the fanfic, it could be that Sakura has her own reasons for not speaking to Sasuke. She might be trying to protect him in a strange way. She could think that by not speaking to him, she can keep him at a distance from some danger that she anticipates. It's a rather self - sacrificing act on her part.
It could also be because of the fans' personal preferences. They may not like the idea of Sasuke and Sakura being together. So they create fanfictions where Sasuke doesn't love Sakura to satisfy their own vision of how the story could be. They might be fans of other pairings involving Sasuke or just don't think Sakura is a good match for him based on their understanding of the characters' personalities.