Now, let’s get one thing straight (ha!): J. K. Rowling was not obligated to make Remus Lupin a queer character. It doesn’t make a whole lot of sense that she didn’t, but no, she didn’t have to. Considering the absolute dearth of queer characters in the text, and the use of the HIV/AIDS analogy, making Lupin queer would have been the clear, obvious and sensible choice — but she did not break any particular rules. She was perfectly within her rights to not portray Lupin as a gay man (even though you never see so-called “AIDS movies” about straight people, but whatever). As thoroughly miffed as I am by the whole thing — and, let me tell you, I am thoroughly, thoroughly miffed — it is easy enough to disregard this particular piece of post-canon information and go about reading Lupin as a queer character as if nothing has happened.
What I absolutely cannot disregard is the fact that Rowling not only chose to analogise a disease that has an overtly queer history — and which disproportionately devastated the queer community — and then applied that analogy to a straight character, but that she chose to act as if the queer history of the disease does not exist."