In Cyberpunk it's gay men and straight women who get the short end but it's generally whoever isn't straight men.
I'd lean towards splitting the difference. Make set sexualities but have an option that lets the player override them. Then just one character max per playthrough is changed and honestly it's not that big of a stretch that one person is bi but leans mostly towards a single gender.
Letting the player override NPC orientation would cripple the game writer's ability to develop the NPC stories and backgrounds before they're romanced.
For example, we learn about Judy's orientation in CP2077 through the story of what happens to her friend and presumed lover Evelyn. That whole side campaign is an organic part of the main plot line. Judy is the most developed NPC in that game, but there is one sequence with Kerry during the Silverhand flashbacks where you see him making out with another guy backstage after a concert, so you don't have to guess what his orientation is. Things like this help establish who the characters are, and I think allowing the player to just flip a "bi" switch if you want to romance them works against character development.
Anyway, it's a fun discussion but all of this is somewhat moot for BG3, because Larian obviously isn't going that deep into developing this side of the companions.
