I really don't feel the scene will have impact, and feelings turning over a compliment runs the risk of making this love shallow in the first place
This is the only point I'm going to respond to because otherwise we're going to be here all day and the fanfiction already exists anyway. The fact that you thought that this was at all a good argument says so much about you. You're assuming that Sakura has permanently friendzoned Naruto and only loves Sasuke because that is what you think for whatever reason. That isn't what most people who like Naruto and Sakura think. So you see it as the bench scene creating a sudden 180 turnaround wow I love Naruto now. No.
Sakura in the story is very, very close to Naruto. He is her most precious person. If you want to argue that Sasuke is, then why then did she attempt to kill Sasuke to protect Naruto? And do not say it's because she loved him too much to let him be evil. That was an absolutely ridiculous claim made by the canon, because it postulates a level of love sufficient to want to kill someone who is in darkness, but not sufficient to actually carry out that murder attempt. That is not at all compelling.
So if Naruto is Sakura's most precious person, but she thinks she loves Sasuke, you can see why people think learning about the bench scene would suddenly flip her views. It's not ridiculous at all. If Naruto is her most precious person, then him being a romantic partner of hers only requires chemistry. And you can easily get chemistry. They had romantic moments in the story.
The bench scene would have been absolutely massive for Sakura. It tells her that Sasuke is willing to come out of his shell just for her. That he likes her.He's attracted to her. Not just to her, but to her imperfections. Not just to her imperfections, but to the one imperfection she absolutely hates. It gives the impression he understands her, when the real Sasuke absolutely did not, but Naruto ironically did. Sakura would have been left with the impression that Sasuke secretly felt a certain way, but was just too shy to do anything after that. That is just horrible to think about if you are Naruto, or even if you are Sakura. I hope you actually understand it now. But I don't have anything else to say to you.