aramis erak
Legend
Gender is not sexuality or sexual identity. Gender is just the question of whether people are male or female. I don't know that I've ever seen a game where the question of whether a character was male or female was never addressed at all.
A game that makes no use of gender other than a descriptive choice by the player has no influence of gender. Gender then matters only if players or NPC's make issue of it. And in many settings, they have no reason to do so, unless romantic or sexual situations are involved. I avoid making them part of adventures, and my players generally avoid those situations, as well.
My current D&D game, it makes zero difference if W is playing her cleric as male or female. That she's playing a genasi claric of light matters, but there is zero mechanical effect, no story effect to date, and only pronoun change. Likewise C's Dragonborn fighter. Both of whom have soldier backgrounds. Of the 7 players & 1 GM, one is explicitly asexual, 4 are explicitly hetero (2 have spouses), 2 have made no revealing comments at all. And I haven't actually asked. Because it doesn't matter.