I am an advocate of this too..
Naruto will definitely in one way or another confess his feelings for Sakura.
But more importantly, I think the purpose of Sai's flashback and him spilling the beans to Sakura is for us to feel the need to have the man itself to confess to the girl.
It wasn't Sai's words nor was it his own feelings so how did Sakura feel after that? ashamed. depressed. etc.
did she even feel happiness about having someone loving her to this extreme?
No right? why?? because it didn't came from the person itself.
That is why I also believe that next time it will be Naruto HIMSELF to say those words and ease Sakura's heart and mind. It has to be NARUTO, not Sai, not Shikamaru not Sasuke.
to hear the words "I love you" as something as a selfless gift and NOT a burden, having no pressure put upon you.. only the person involve can do that.
I believe that the purpose of a confession from Naruto is to wrap up all the developments the two made.
To clarify the things they have been dealing with throughout, to ease out the creases.. the feeling of not being enough, of not being worthy of the other..
Naruto's words is proven to be powerful enough to move anyone and make them believe in him.
Like its therapeutic.
If he finally confesses his feelings, I am sure it will erase Sakura's doubts about herself and she'll be more confident to relay again her feelings for him. this time with pure confidence and no other person to hold her or him back.
Because Naruto himself can prove that his feelings for Sakura weren't something like a curse (yes Sai, i still think you are adorable).. but something like strength. I know this might sound cheesy (bec. IT IS) however Kishimoto seems to have a penchant of springing back things from the past to be used in the present.
*insert Haku's line* one of the most impactful words to Naruto. She was never a burden to Naruto, she is one of his strength and so is he to Sakura. If Sakura dropped all her insecurities she has with herself regarding not doing enough for Naruto, then I'm sure that boy won't have to question her feelings this time.