The most you could accuse Harry Potter of is being classist. Like yeah the death eaters are bad nobles but all the heroes except Hermione Granger come from old and storied houses.
I disagree; classism (particularly the way it works in British society) is a theme that was directly explored. I don’t think the movies did a good job of communicating it, but the books make it abundantly clear that the Weasleys were both poor (or at least working class enough that they didn’t have nice things)
and looked down upon by other wizard families for it. Even being purebloods didn’t cancel out the classism; Draco makes fun of Ron for his family’s reputation when they first meet.
It’s implied that this is one reason why Mr. Weasley empathizes with Muggles as much as he does, and that his reluctance to embrace Wizard Supremacy has limited his upward mobility at work.
Wether she retconned Dumbledore to be gay or not we will never know unless she tells it outright. But I read Deathly Hallows as a 13-year old. And even I thought that it might have been more than just an intense "friendship" with Grindelwald.
I was starting college when the last book came out. Speaking as someone who was never into fanfic or shipping, I could also see the subtext without squinting too hard. There was
definitely more substance there than with Remus/Sirius, the pairing all the HP fujoshis were obsessed with at the time.
Do I think JK Rowling envisioned Dumbledore from the start as a gay icon and has been dropping hints about it the whole series? Highly unlikely. Do I think she just impulsively pulled “Dumbledore is gay” out of her ass on the spot during that interview solely for woke points? Also highly unlikely.
I think it was an idea that developed organically in the process of planning out the backstory with Grindlewald, but not one that she had the ability or the need to expand on in detail at the time. Apparently she had told the film writers about it before it became public knowledge (they were going to add some throwaway lines where Dumbledore waxes nostalgic about a female love interest from his youth), so it checks out.