Often, anime ops spoil the story by showing clips or images that hint at major events or twists. This can happen if the creators aren't careful in their editing. For example, a character's transformation or a big confrontation might be shown too early.
The opening of 'Fullmetal Alchemist: Brotherhood', 'Again'. It starts with the two brothers, Edward and Alphonse, in their search for the Philosopher's Stone. The opening is full of scenes that represent their adventures, their battles against the Homunculi, and their quest to regain their normal bodies. It really does a great job of setting the tone for the story.
Anime openings that tell a story enhance the viewing experience by building anticipation. For example, in the opening of 'Death Note', it shows Light Yagami's discovery of the Death Note and his initial foray into using it. This makes the viewer eager to see how his actions will play out in the actual episodes. It gives a quick preview of the main plot elements.
Well, one major spoiler is a surprising plot twist involving the main character's true identity. But I won't go into too much detail to ruin it for you!
The Genshin manga can potentially have spoilers. It might show events or details that haven't been encountered in the game yet. It's best to approach it with caution if you're worried about spoiling your game experience.
Konoha could feel a sense of wonder. Since fanfiction can be very creative, the Naruto openings in it might be full of unexpected twists and turns that make Konoha wonder about all the possibilities within the Naruto universe.