Personally I don't really care if there's more, then again if you asked me about anyone's sexuality in the game I'd go "eeeeh i don't know" very few npcs have partners and only a few show interest in anyone, Thancred was a bit flirty at one point towards women and Urianger liked the moon lady, but I think that's about it. I'm not gonna look at a character differently because of their assigned sexuality.

focus on if a npc is likeable rather then who the npc likes, for all I care everyone is bi and its a giant bang circle, but if the npc is (not) likeable ill (not) not like them. What they do in the spare time in terms of sexuality hardly needs to be explored.

If SE would constantly show straight couples in your face I'd agree to keep some balance, but i do not recall many ... There's the chonky cat lady and her husband ... but after that I'm blanking.

This game is a "power of friendship" game, saying gaia and ryne are a couple is about as close as saying rauhban and nanamo are ... maybe, maybe not, depends on how much you want to read between the lines.