I'm about the biggest proponent of "assume ignorance before malice" that you can find... but the amount of ignorance about the work of JK Rowling is pretty troubling. Most people don't even know what a "TERF" is, and those who get the acronym explained to them divorced from the underlying philosophy tend to simply agree with it because "feminism means female, right?". This empowers transgender exclusionists in the same way that the erroneous assumption that white people have superior mental abilities empowers the Ku Klux Klan. It's a seed that may have been planted by a white supremacist, but is watered by otherwise decent people. The idea may have originated from 1950s white supremacy, but it was taught and retaught so much that it became an accepted part of culture.
Harry Potter was a big part of Y2K culture, I'll grant you that. For a grand long while, I was caught up in it, too! I watched the films, I read the books, I had action figures, LEGO playsets, video games, and I wished beyond all reasonable hope to receive my owl and go to Hogwarts. However, I was not able to read "between the lines" as it were, because I was so young, and even if I had been able to see Joanne's racism, imperialism, antisemitism, and queerphobia, I would have been able to dismiss all of it because none but the antisemitism would have affected me personally.
That's the big thing with "assume ignorance before malice". The definition of "malice" is often extended to mean continuing a behaviour while knowing it's bad on the grounds that it has no perceived effect on one's life beyond the behaviour itself. This more accurately defines "ignorance", because people often don't realise that everything is connected through collective behaviour. The phrase, "it's not that deep", has done incalculable damage to critical thinking in this way, by trivialising the behaviour. In the case of Harry Potter, most people are not transgender. Therefore, they hear about the series' inherent transphobia and JK Rowling saying shit like "everyone who reads Harry hates trans-women" and are able to rationalise it because it doesn't affect them; i.e. "it's not that deep". At the same time, they can't understand why some Karen holding a bible was arrested for kicking in stall doors in the public restroom in search of the "transsexual menace". By interacting with JK Rowling's work in a revenue-generating manner, they are allowing her to carry on with the militant rhetoric that empowered this Karen to do that in the first place.
Now, at some point, ignorance becomes malice. If someone intentionally shields themselves from knowledge, they can weaponise their ignorance so that, in all cases, they can claim that they "simply didn't know". However, sheer ignorance can never become malice on its own. In order to filter out information to stay ignorant, they need to be able to recognise what information to filter; thus, they learn just enough to know that their behaviour is wrong, but not enough to know how wrong it is. If someone hears that the Quidditch League changed its name to Quadball because of statements that Joanne made, and then cuts out all other information, they know that she made some kind of polarising opinion on some subject or another, but they can't be bothered with the annoyance of thought, so they intentionally do not learn what caused the name change to occur. From this point onward, they filter out everything they see on their news apps having to do with JK Rowling so as to not learn anything new that might cause them to need to find different media to interact with.
I don't think the people who make Potter-focused CC on ModTheSims are evil, I don't think they're transphobic or racist (beyond the factory racism built into all white people). I do, however, believe that they and everyone else who continues to put their Hogwarts house in their social media biographies and write HP fanfiction need to come to the realisation that they are sheerly ignorant to the challenges of being trans, Jewish, and/or not white in a world full of people who just can't give Harry Potter up. The easiest way would be to just read a few of her tweets on the subject. And, yeah--it'll hurt. It will hurt bad to realise that your comfort characters have all this white supremacist shit baked into them like yeast in bread. But it won't hurt half as bad as a state legislature, bought and paid for by faux feminist PACs that didn't exist before Joanne Rowling planted the queerphobic seed in their true crime tainted imaginations, banning gender affirming care and adding 15 levels of contradictory regulation to hormone-replacement therapy.
Ignorance of discrimination is bliss for everyone except the ones being discriminated against. Find a different book to read.