Actually, Dumbledore was gay. He and Grindelwald were lovers in their youth. That was part of the story, not after the fact. There were clues there all along. Not enough to be obvious to kids, but I was an adult when I read the stories and I wondered about it until the later books, and it became more clear.

There was a fair amount of inclusivity. Dean Thomas was black, Parvati and Padma Patil were Indian, Cho Chang was of Asian ancestry
etc.

There was the paradox of the Malfoys and the Longbottoms as far as wealthy, white, aristocrats. The dynamics with the Black family.

The prejudice against mudbloods.

E.L.F. and Dobby.

Hagrid was half giant.

The entire castle was an homage to people who do not accept the status quo. The 'normal' narrative.

I don’t think she wrote it with the intention of inclusivity. I think she wrote a school, which has all sort of people in it. I think the biggest lesson here, is what does it matter? What does it matter if Dumbledore is gay or not, when he is a mentor and respected teacher to you? The story is told through they eyes of Harry. Why would Harry have cares whether Dumbledore is gay or not? Whether Hermione is a pure blood or not? Whether Ron was poor or not? These were the people who loved him and wanted him to live. To survive that horrible prophecy.