I like the idea of characters' sexuality being influenced by the players' willingness to pursue them. I'm gonna be a little shit, though, and say it's 2020. People apparentely got into an uproar over female Mandalorian armor. Strong independent lesbian character turning straight because male would attract all kinds of crazies.
I remember a lot of people getting angry because you couldn't do that with e.g. Sera in Inquisition and suspect that was the likely source of a lot of the hate for her, which was often excused as not liking her "stubborn" attitude. I don't really see the point of influencing a character's sexuality though: that's not really any different to the playersexual stuff we have already. I'm slightly on the fence about the subject; using DA as an example, I preferred Inquisition to DA2 but I suspect I would've had a very different opinion if the only characters I liked were unavailable because it wasn't a thing.
This would not work in Inquisition simply because there characters personal quests are literally tied to their orientation, as if orientation is most important part of their personality. This is why I don't like lock on orientation, it not only cuts off some of content for you, but also often makes characters more boring. This is fine only with Solas, and only because He is something more than your companion... But Dorian's quests are a real cringe. In DA2, you could only think about Anders, because he had a "friend". But everyone else looked pretty normal, and it was better because their stories didn't cling to their orientations, they were focused on their personalities.
In BG3, I see problem only in races, I hardly believe that Astarion sleeps with a gnome after he called them animals.