That is an interesting clause. It certainly begs the questions "what settings are appropriate for LGBT folk," and "how is that appropriateness determined."
The sheriff of Sandpoint, the town and centerpiece of the very first Paizo Adventure Path, is in a homosexual relationship with the theater owner.
But other than that, all the single NPCs are ambiguous - by design - so they can be objects of romance for any PC.
However, representation is still on their mind. It was noted by Paizo staff members (James L. Sutter IIRC) that when writing City of Strangers, diversity was on the author's mind and they worked to include lots of straight and gay characters in the book to create a representative and diverse city.
But forgot women.
It was pointed out to him too late that he'd forgotten to include female NPCs of note.
Which is the thing, if you're not careful and thinking about diversity and representation, it's easy to make all the important NPCs white males or relegate other races/ethnicities, genders, and sexualities to backrgound roles... if at all.
And... in what way was this adventure dramatically worse for this "oversight"?
When I say equal representation doesn't matter, people tend to assume what I actually mean is that it matters a lot to me and I am opposed to it.
But that's not it at all. It's much simpler than that.
It. Doesn't. Matter.
If inclusion of a particular type of person wouldn't fit smoothly to a particular situation, don't shoehorn it in. And if it would... then that doesn't mean you're now required to shoehorn it in. It just means you should do what makes sense to you in that situation, and include what seems reasonable.
Making a bunch of extra effort to be "inclusive" is tantamount to saying that it's important, and that it wouldn't naturally be included, so you need to force it.
Why? What is gained by that?