Im pretty sure we don't need to worry about it.
the opening Hinata appears for all of a couple seconds while Sakura appears for quite a bit longer, evne the hand holding is vague if you haven't read the manga.
As for the ending, Sakura appears twice at least, and again the hand holding is vague, in the end of the ending Naruto is standing next to Sakura, and Sasuke as poart of team 7.
the hand holding as someone mentioned earlier is done in a context of unity and togetherness.