So Dumbledore is gay. I’d say So f***ing what? Who really cares?
JK Rowling could do with her characters anything she wants. She is the author so she have author’s right. Dumbledore exists only in her imagination (and later in the imaginations of her books readers). She could kill him, thrill him, kiss him with another beautiful character (or even awfully ugly one).
Nobody complaining when the charismatic characters dies, even if they dies in bloody accidents or feeling intense unbearable pain. But when the author said that the famous and long loved character was gay the fun begins.