Poe Dameron is probably only accidentally a gay hero. He wasn't originally meant to survive the first act of Star Wars: The Force Awakens according to writer/director J.J. Abrams, so he doesn't have a real arc of his own. On paper, Poe Dameron is just a device to advance the plot. It's in Oscar Isaac's performance that he becomes something special, and someone Abrams knew he had to keep around.
Isaac gives Poe Dameron his charisma and smoldering intensity, and because his primary (human) relationship in the movie is with John Boyega's Finn, he gets to direct that charm and intensity towards him. In one of the characters' most pored over scenes together --- a scene that only exists because of Poe Dameron's reprieve from death --- the pilot gives Finn a look that's indistinguishable from lust, even biting his own lip as he tells him to keep the jacket they've come to share. It's one of the gayest things I've seen in a blockbuster movie, in the most positive and celebratory sense of the word, and it gave us reason to hope that Poe Dameron could be Star Wars' first onscreen gay hero. But is Poe Dameron actually gay, and what happens to our hopes and dreams if he's not?