Not only was it not a central theme—it wasn’t a theme at all. It just didn’t come up because—here’s a news flash—books intended to be read by children for fun very seldom deal in depth with the sexual orientation of characters, particularly adult characters.
But people on both sides of the social issues spectrum (NOT just conservatives) do care, for some reason. A lesbian friend one time told me, sincerely and as though this was something that ought to be clear to the dimmest bulb, that Winnie the Pooh was “obviously” gay. Because he was sensitive, I think. Really. I’m not kidding. Or maybe she’s looked really closely at the illustrations and has determined that he’s wearing eyeliner or something—I don’t know.
So you have pro-gay activists out there trying to prove that various influential people and characters are gay, and in this way demonstrating how normal homosexuality is (and in a few cases trying to prove that it is “better” than heterosexuality), and you have anti-gay activists doing the same thing in order to show how perverted and sinful the world is. I’m kind of tired of both, to be honest.