In retrospect, I can see how they could choose Loki. He's never been seen with a woman, he's mocked the relationships of Thor/Jane and Clint/Natasha, and he has the ability to take the form of other people.
They might not ever go that far, but Loki is about the best candidate for LGBT because in his 1000+ year life, he probably has fucked men and women, changed from man into a woman, etc.
Question is, is this needlessly acknowledging that LGBT group or is this a way of extend the story of Loki beyond bad guy/bad guy with a heart/anti hero/hero into the God of Mischief who dips his pen in different ink wells?