You're assuming the movie is NH because of well crafted trailers and concern. It's very likely the movie is what the professor told his student on that page, a way to send off Hinata and have her character addressed and story-line fulfilled by having her own journey, at the same time making Sakura realize her jealousy (which she has shown in all moments Hinata has shown love for Naruto that she was present for). It's a common literary device, you have the main female character confused about her feelings for the main male, which are resolved when another woman shows credible interest. I think this movie will have Hinata play a larger role, have her feelings addressed, and her story resolved but I don't see NH happening. It just doesn't work, fit, or make sense with everything else Kishi has written and put out throughout Naruto.
This movie will be about more than just Hinata's first love, it will also be about Naruto's. As you've suggested, if NS hasn't happened in the movie, then it wasn't resolved in the manga. Which means it has to be in the movie. Kishi didn't spend all that time developing characters, physically being exhausted drawing them, wrapping Kushina's character around Sakura and using her as a means of sending a NS undertone to just not resolve it.
Again, gotta leave the caveat that all this may be false if Kishi just got lazy and let SP dictate the end of his story, which even knowing Kishi, I don't think He'd do. The man has always been NS, its what he's given the most time to, follows in line with the literary style he's had all along, and is the only way to not break Sakura's development and Naruto's way of ninja.
I'm not assuming anything will be canon. I'm pointing out the likelihood of events based on information we so know, because people's "positive" conclusions are so unlikely that it's making me feel worse.
Hinata gave Naruto a romantic scarf.
"
It must be her giving up on him!".
Sakura tells Hinata something and she blushes.
"
Sakura must be encouraging Hinata to give her boyfriend a romantic scarf!"
I'm not going to even bother with what someone's professor said. She told him the series from her perspective, it's entirely possible she didn't even tell him all the facts for him to give him a balanced opinion. Plus, that would be assuming Kishimoto is consistent, which isn't very convincing at this point, now that he's added new childhood memories between Naruto and Hinata.
