Lol The bold part and the arguments for NH you made till now prove your first statement is a lie
Naruto has done nothing to show he is into Hinata romantically. Vice versa is true
Naruto can accept the scarf without romantic undertones.Let's say a girl loves you and you.You love another girl.The first mentioned girl offers you a scarf. You will accept it just not to hurt her feelings It doesn't mean he loves her
Also we are literally arguing on head canons.First the mystery woman is wearing sleeves.Hinata doesn't.The mystery woman is having spiky hair.Hinata is as of now shown to have flowy hair,not spiky.
Concluding that Hinata gave him the scarf when it could be literally be anyone is foolish because we have no proof she gave it to him
Also I will LOL so hard if in the movie all of them are wearing scarves because its winter and the mystery woman turns out to be a sales woman