I would go crazy and scream canon if I was a NH fan 
If we had Sakura on Hinata's place, I would be mildly happy, not regarding it as something big nor something bad (despite of sad faces). Sakura is the main heroine, whose development goes much further than her relationship with Naruto, so she would have a lot of non-romantic reasons to be there. Naruto and Sakura have always shared both happy and sad moments in their lives, this is part of their comradeship (and love), so them being in any kind of dynamic would seem so very natural (not like it does now with Hinata). Even if it is connected to them personally, it would be a good thing probably. Like that scene in RtN, when they talked near the fence, not seeing each other. It was a complicated moment for both of them and they had a very apparent conflict of interests (that made me even guess whether Naruto would chase Sakura with such persistence if he had a family), but the way this scene was shown it was incredibly pro- NS. They were practically reading each other's minds, talking with their souls. They didn't need words any more to understand each other.

(I don't know who did this picture)
In Hinata's case her only shared emotional ground with Naruto is Neiji, which is why it is either rejection or mourning to me. I also think that mourning in this manga has been portrayed as a collective experience with people helping each other to move on. Actively, I mean. Especially when there are three years between the incident and this "mourning" scene. I would rather expect Naruto to have a sad smile on his face and maybe talk to Hinata about their shared experience with Neiji. So it doesn't seem like a "trip to the grave" kind of scene.
On the other hand, if Sakura were on Naruto's place and Naruto on Hinata's, I would be kinda worried for NS, because I've had enough of Naruto chasing after Sakura with her neglecting him for various reasons (who am I kidding - there is just one reason with hot haircut). I would wonder whether this is a forshadowing of Sakura's decision to pursue Sasuke till the end, which is a tiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiny bit less ridiculous than Naruto giving up on her. This is also the reason why I think NH should be worried - chances of Naruto rejecting Hinata are too damn high.
Edited by Alessa, 23 October 2014 - 02:24 PM.