The best part is that you and your ilk seem most offended by the innocent suggestion that Luke might not be totally, 100% straight. Who cares? You do, obviously. Why does it matter? It never seems to matter when a character is heterosexual, of course; anything else is subject to complaints and, yes, offense at how "forced" and shoehorned-in it all is. Maybe after his life settled down and wasn't a constant parade of stress and trauma, he realized he likes boys too, or girls not at all. Maybe he didn't. It doesn't really matter either way unless or until the storytellers make it a plot point, and even then fans are free to imagine what they wish.
For people who are generally under-represented in popular media, sometimes this kind of speculation exists as an outlet for them to feel normal and normalized in a culture that often excludes them from that conversation. Get over yourself, honestly.
I mean, I'm fine with lgbt people, but if they'd just keep quietly to themselves in their closets and stopped shoving their sexuality in my face by existing that'd be just dandy.