Assuming he would have gotten to speak to her, her reaciton would have been quite different from what people think. What she wanted from Sasuke was acknowledgment.
for Naruto to speak that daydream as himself would quite frankly have thrown her for a serious curveball.
at the time she was under the misconception that he didnt understand her at all. for him to stand there and say what she was daydreaming would have stunned her.
its safe to say also given Kushinas statement about what minato said about what she viewed as her worst feature, that for naruto to say such a compliment to her would have been a powerful moment.
now im not saying she would have jumped right into his arms or anything. but she would have almost certianly began to look at him differently and a conversation could have ensued similar to what occured in canon.
Yeah, look how she reacted to Rock Lee's words in the Forest of Death- and she has nothing but feelings of friendship toward him; unlike with Naruto where as early as chapter 5 she was exhibiting a subconscious romantic attraction to him. Yeah, if Naruto had said it without henging into Sasuke's form I think she would have been stunned speechless and just stared at Naruto wide-eyed. Naruto might have perceived that as a negative reaction but I think it would have triggered a bit of Sakura's subconscious attraction to become conscious a bit quicker and it really would take on a triangle in her mind, her crush on Sasuke vs this other kind of slowly growing romantic attraction to Naruto.