The Weasleys' understanding could be both broadened and a bit muddled. On one hand, they might see new interpretations of old magic or different ways characters could have interacted. For example, if the fanfiction explored a different side of Snape's actions in Book 6, it could make them think. But on the other hand, they might be confused as some fanfictions can be really out - there. They'd have to sort through what was based on real knowledge of the wizarding world and what was pure imagination.
Their view might expand. They'd see different takes on the wizarding world that they hadn't considered before.
Dumbledore could gain new insights. Fanfiction might explore the social aspects of the wizarding world in ways he hadn't considered. Maybe there are stories about how the different houses interact in a more complex way than he thought. This could make him reevaluate his own views on the unity or division within Hogwarts.
Their view could become more confused. Fanfiction can present all sorts of alternate universes and character developments. The Death Eaters, used to a very specific view of the wizarding world under Voldemort, would find it hard to accept different versions. They might see the wizarding world in fanfiction as a chaotic and wrong place, which would make them double down on their own views to feel more secure.
The wizarding world would likely be plunged into a state of despair. Harry was seen as the 'Chosen One' to defeat Voldemort, so without him, there would be a sense of hopelessness. Voldemort would probably have free rein to impose his dark rule without much opposition at first.
The wizarding world would become more open to Muggle - borns. Harry being a Muggle - born advocate would ensure that there are no discriminatory practices against them. He might also make Hogwarts more accessible to students from all backgrounds, not just those with a magical family history.
In fanfiction, Harry Potter can change the Wizarding World in many ways. For example, he might introduce new spells or magical concepts that were not in the original series. He could also have different relationships with other characters, which in turn would affect the social dynamics of the Wizarding World.
It could deepen their understanding. They might learn new aspects of the wizarding world that were not fully explored in the original books. For instance, they could discover new magical creatures or spells through the fanfiction.
If Harry Potter had the Infinity Stones in fanfiction, it would completely transform the wizarding world. Magic as we know it would be redefined. Harry could potentially use the Time Stone to go back and prevent Voldemort from ever rising to power in the first place. The Reality Stone could be used to create new magical landscapes or even change the nature of existing spells. With the Power Stone, he might be able to enhance the power of every wizard and witch in the world, making them more capable of defending against dark forces. Overall, it would be a radical shift from the original Harry Potter universe.
If Harry invented spells like 'Teleporto Instanto', which allows for instant teleportation anywhere in the wizarding world, it would completely revolutionize travel. People could go from Hogwarts to Diagon Alley in a blink. It would also change the way battles are fought as wizards could quickly escape or surprise their enemies.
Their relationship could lead to a more inclusive wizarding world. If Raven has different beliefs or magical practices, it might encourage others to be more open - minded. For example, if she's into a more spiritual form of magic, it could inspire new research and study at Hogwarts. Also, their marriage might set an example for inter - house or even inter - species relationships, which were previously not so common.