I don't think it's a "heterosexual vs. homosexual" issue and it may be a mistake to look for parity in the framing device for an intentional story.
It's more like the writers saw that queer stories have historically gone untold in this medium and decided to tell a few of their own. How many prominent queer relationships can you name in over a quarter-century of RPGs?
EDIT:
Please meet me halfway here. I am really trying to assume good faith.
What parity/with what? I'm looking for more balanced and nuanced representation instead of overuse of tokens. Not constant reminder that Baldur's Gate is California of faerun.
The existence of LGBT people in a work of media, especially at the forefront of said media, is not the overuse of a token.
We define tokenism as:
the practice of making only a perfunctory or symbolic effort to do a particular thing, especially by recruiting a small number of people from underrepresented groups in order to give the appearance of sexual or racial equality within a workforce: the use of gay supporting characters is mere tokenism.
The appearance of these couples is not symbolic or perfunctory, whereas further addition of heterosexual couples for the sake of "balance" would be a form of tokenism.
