Using Labels on Character Sexuality (to add subtle worldbuilding)

For my fantasy story, I was thinking of having the characters say their sexuality, but in a different way. In most stories that do representation right, they show it, but do not directly say it. For my world, they do say labels, but the twist: They only use old, medieval terms that are vague, and leave the audience to figure out the rest. However, I am unsure if this will work well or not. The idea is that, as the time period changes, the used labels start to change a bit over time, until the steampunk storyline, where they actually start using modern lgbtq labels.

How could I use this method for worldbuilding, but not make it seem like it is pandering?