If they’re a reader of fanfiction that is typically one of the major changes to the story that’s done. Fanfiction has effectively rewritten the entire series to be more palatable at this point. Bonus points that you can read it without giving Rowling any money too.
If the fanbase needs to rewrite the entire series to be “more palatable” that might indicate something about the series itself.
Might be time for people to just move on to a different series.
That’s a tall order with how most people act. Disney vibes anyone? There were few things that could capture a whole generation’s imagination so strongly, and people want to bond over it. My stance is taking what you like and making new things is how we get new series’s, and fanfic has it’s place in that.