Well, a number of fans are divided. Some feel that the insults are a form of character assassination for Sasuke, as they view him as a more complex and redeemable character than one who would just randomly insult Sakura. Others, though, might see it as a way to explore the darker side of their relationship and how Sakura can grow from being insulted and become an even stronger character.
Generally, fans have a mixed reaction. A large portion of fans who support the Sasusaku relationship feel betrayed or disgusted by such fanfictions. They feel that the characters have been misrepresented. On the other hand, a small group of fans might view it as a way to explore the limits of the characters and the Naruto universe. But overall, it is a very controversial topic within the Naruto fan community, with more fans leaning towards not accepting this kind of extreme deviation from the original story's character arcs.
Fans have a wide range of reactions. There are those who are vehemently against it. They have a strong emotional investment in the Sasuke - Sakura relationship from the original series. Then there are others who are more open - minded. They see it as an interesting exploration of different relationship scenarios within the fanfiction world. These fans might engage in discussions about why the author chose to take such a route and what it means for the characters' development in the fanfic.
A third group of fans might simply ignore it. They are so set on the original story and the positive portrayal of Sasuke and Sakura's relationship that they don't want to engage with any fanfic that goes against that. They might consider it a disrespect to the original creators' intentions for the characters.
There would be other fans who might be intrigued. They like to explore different 'what - if' scenarios in fanfiction. They would see it as a creative way to explore the characters in a new light, even if it goes against the canon. However, they would also be aware that it's just a fictional alternative and not the real Naruto story.
Some fans are horrified. They love the characters as they are in the original series and any deviation that involves such a violent act against a main character like Sakura is unacceptable to them.
Most fans are likely to be quite shocked and disappointed. Since Naruto and Sakura have a long - established relationship in the original series, seeing Naruto cheat in fanfiction goes against what fans have come to expect. It's like a betrayal of the characters' original personalities.
Some fans are really into it. They enjoy seeing different takes on the Naruto and Sasuke relationship. It gives a whole new dimension to their dynamic. However, some fans might be a bit put off as it goes against the more traditional view of their relationship in the original anime and manga.
In some fanfictions, Sakura may be determined to find Sasuke and bring him back. She could set out on her own journey, facing various challenges along the way, and growing both as a person and as a ninja in the process of trying to reunite with him.
Sakura would be over the moon. She would blush deeply and look at Sasuke with so much love in her eyes. She might be at a loss for words for a moment, but then she would find her voice and tell Sasuke that she has been waiting for this moment her whole life. She would also feel a sense of pride that Sasuke has chosen her, after all they have been through. And she would immediately start thinking about how to share the good news with their friends, especially Naruto, who has been like a brother to her and has also been a part of their journey.
Sakura might be initially frustrated. She's used to Sasuke being in control, so seeing him drunk could be a bit of a shock. But then she'd probably feel a sense of protectiveness and try to sober him up.