In RPGs, there are a couple of ways that developers have handled romances—and, specifically, sexuality within those romances. The first route is to have specific orientations for each character. For example, Zevran in Dragon: Age Origins is bisexual, whereas Alistair is straight.
The second route is to make companion characters "playersexual" ala Baldur's Gate 3—they have canon sexualities sometimes (Astarion and Karlach are canonically attracted to, at least, men and women) but they're never specifically set in stone, and will adjust to the player's interest regardless of their gender.
It's… an interesting third option, to be sure, and I have mixed feelings about it as a pansexual man myself. I think what Busche says about the off-putting nature of orientations changing to the player's whim is fair enough—but I would also argue that, in such games, orientations that don't gel with playersexuality are never set in stone.
For example, Astarion and Karlach from Baldur's Gate 3 are canonically bisexual or pansexual—Astarion has fallen for men in his past, but will also go off and have a fling with Lae'zel, whereas Karlach's origin character story sees her fantasising about both men and women in a particularly raunchy camp interlude. Gale, on the other hand, has only ever had (unless I missed a secret scene where he looks into the camera and says 'By Mystra, I love men') experiences with women. It's never confirmed, however, that that's all he's into.
As for the playersexual vs canon sexuality debate, I'm personally fine with both, and I think they both have their strengths and weaknesses. Playersexual companions give some authorship of the characters over to the player—allowing them to fill in the gaps (stop giggling) of their party member's romantic attraction. They allow players to represent themselves with whatever backstories they'd like to inject into the setting.
Canon sexualties, such as those in Dragon Age: Origins or Inquisition, provide less player authorship, but allow for more overt discussions about sexuality within the text and worldbuilding. They also tend to be stronger when we think about why representation is important, and how—though there's also a lot more room for things to go wrong. I love Zevran with all my heart, but he is very promiscuous and flirtatious, which is a negative stereotype—mostly harmless, especially given he turns out to be a deeply romantic person, too, but still.
Anyway, I won't know how I feel about Dragon Age: The Veilguard's approach until I see it for myself, but I can't escape the feeling that this is just playersexual characters with more steps. I fear, also, that we might get the worst of both worlds—no player authorship, but also no interesting discussions of sexuality. I'll reserve my full judgement until the game's actually out, though.
I do, however, think the idea of characters going off and having romances with each other is fun—people don't just wait around if you don't shoot your shot.
