Hmm, this is a good question. I'd say that the purpose of this community for me is to highlight characters who are sexual and gender minorities, not just the experience of marginalization. The story you're describing would probably still have a place here, as I imagine the characters the protagonist encounters could have identities considered minority in the cultural context of you, the creator. I think it'd depend on how the idea was handled. For instance, a story where someone who's straight and from a heteronormative culture is drop-kicked into a homonormative culture would fit, particularly if the story spent time with the characters from the culture highlighted in the story. A story where a modern Western straight-identified, cisgendered woman is drop-kicked into 1600s Europe would seem to skew focus, even though her gender performance might completely violate all the rules in that older historical era.

Does that help clarify, and does that seem like a meaningful distinction to draw?