First there was The Avengers, and then there was Justice League, but surely studios aren't going to rest on their laurels when it comes to the whole "band of heroes" template. These two may be the crème de la crème, but they're not alone. The Watchmen, Doom Patrol, and The Outsiders are just a handful of examples, and they're not alone. In fact, one of the teams that could easily follow in the footsteps of groundwork laid out by both DC and Marvel alike is Teen Titans. Definitely aimed at a younger audience per its name, Teen Titans happens to include the young hero named Bunker. Not only is the character gay, his ability to produce psionic bricks as weapons is meant to symbolize the bricks used in protest during the Stonewall Riots in 1969.
Related: Most Powerful Teen Titans
In the Marvel corner are the Young Avengers (whose name should speak for itself). Alongside fellow teammates like Miss America and Marvel Boy are Wiccan and Hulkling, two chips off the ol' block who just so happen to be gay. Wiccan is the son of Scarlet Witch, and when he's not wielding magic against ongoing onslaughts of villains, he's maintaining a healthy relationship with fellow Young Avenger, Hulkling (take a guess as to who his parent might be). In a mainstream superhero movie targeted at a younger audience, putting this kind of relationship on display has the potential to fight the stigma of homosexuality having negative effects on budding children.
The Long Shots
It's one thing to hope for the best when it comes to greenlighting progression, but limitations will always be that irrepressible beast blocking the way. So, as encouraging as it would be to have all-encompassing representation in superhero adaptations, don't bet against reality.
But let's stay hopeful. In rooting for the underdogs, there are a handful of other LGBT superheroes who could potentially pack a punch in their own movie - if not in the most expected ways. For example, now that Hugh Jackman has hung up his hat with Wolverine, there is room for a newcomer. Instead of going down a familiar route, why not approach the character from a different angle and portray as him like in the Earth-12025 universe? In this version, Wolverine goes by his birth name, James Howlett, and he's in a secret gay relationship with Hercules (though the two are eventually outed).
Now, assuming Wolverine enthusiasts refuse to get on board with this sort of change, there are other possibilities. To piggyback off of DC's dive into The Batman, they can easily counter it with Batwoman, a US veteran who was discharged from service on account of her sexuality, who then reinvents her natural proclivity towards justice with a costume and cape. And to continue the whole piggybacking angle, Colossus has made plenty of film appearances (most recently in Deadpool), but never on his own. Nor has Bobby Drake (a.k.a. Iceman), a character who has the potential to be a perfect choice for leading a standalone story (though, in his case, something along the lines of a show on The CW would probably be a better fit, a la The Flash or Arrow).
Rounding out some hopefuls are Northstar, the very first openly gay superhero, Apollo and Midnighter, an openly gay couple who have literally trudged through the deepest pits of Hell for each other, and Lord Fanny, a transgender member of the Invisibles. These are definitely long shots, but assuming studios are willing to adapt to the times, maybe some of these aren't as far off as they might seem. Given the fact that the X-Men universe currently has six different projects in the works, it's clear to see that the superhero genre is by no means in the business of trimming fat, which serves to benefit these chances all the more.