Feels like the way of the world. There are 200-300 people where I work. Of the younger generation, way more are gay or transgender than us older folk. In fact, I don't know of *anyone* over 40 at work who is either, and there are *at least* a dozen in the under 30 crowd (and, being the post office, a deeply 'old folk' heavy workplace, the majority of us are over 40!).
So it's hardly a surprise to me that a younger generation of comic characters might have a higher percentage of (openly) LBGT folk. That seems to be how it works in real life.