Naruto and Sakura have something major that Naruto and Hinata don't have: Development and screen time together. That isn't by mistake. As a writer you foreshadow and build up to things, one example is Obito/Sasuke in part 1(the hints and themes of falling from grace and friends/rivals becomming enemies). There's been a build up with these two, especially part 2, and that's important.
Sakura went from seeing Naruto as a total pain to being confused in the databooks. Add the lingering feelings Naruto still has for her and it's pretty likely (last time on screen together he called her chan and when he went after Sasuke before his heart was broken making that promise to her).
The likely ending is Team 7 ending up like Tsunade's team(all alone). Hinata is a flat character in this story.
Exactly. That's one thing in plus.
Plus, there were also some other hints from Kishimoto relating Sakura's feelings in the Databook. Don't exactly have it now but anyway, might come back afterwards.
The thing is that as a relationship, no matter which one, they were the best developped characters. From considering Naruto a pain in the ass to risking her own life for him and above that, even puttin Naruto's feelings above her feelings for Sakura, well, that measns something.
And yeah, in the last panel we could see like some sort of Team Sannin but I do have the impression that Naruto will do what Jiraya was never able to do. In any term. Meaning finding peace, confessing his love and stuff like that.
But as I said, in the end Kishimoto decides. We can argue here all along.