Well, if the NPCs are hetero/gay and not both bi, then someone gets more companion romances than someone else, so I'm not sure that's going to happen, either. Hmmmmmmmm. 
People say the elves will both be bi because they always have been, or because if they're not one side wont get a non-human romance. Is not getting a non-human romance something they would likely place over everyone getting the same amount of companion LIs? I don't know.
It seems like Cullen will be the only male NPC and he doesn't appear to be gay. So unless there is another male NPC I think the gay character will probably be companion. I would be unfair if the gay option was a companion, but the lesbian option wasn't, but then Bioware may not count NPC LI as worse than companion LI. In context of the companion gender imbalance David Gaider said:
There seems to be quite the laser-like focus on party members. Understandable, perhaps, considering those are the characters with whom you spend a great deal of time... [...]
We. however, approach the equation a little differently. [...] Gender diversity is also considered, but when we look at it in terms of representation, we look at it in terms of representation across the entire story—not just in the party.
Considering Inquisition takes place in a world where many (if not most) of the world's power players are female (the ruler of Orlais, the head of the Chantry and the Circle of Magi, possibly the ruler of Ferelden and others...not to mention the many characters outside of the party with whom you will also be deeply involved.
Could mean they think companion romances are more important than the NPC romances, could mean they think they're the same. He says he understands why people focus on the party, but then he says the gender balance across the whole story matters, not so much the gender balance in the party. Of course there's no direct conclusion for romance options, but I think it's an insight into what matters for the team.
I'm not sure the team counts elves as non-human LI. They obviously didn't counterbalance Zevran with a female elf. His female counterpart was human. But I do think they might count a qunari as non-human.
It sounds sort of serious when they say they want to explore sexuality. I think the safest way to do that would be to go with humans, because elves and qunari are fantasy. Do you know what I mean? Just a thought.