You guys just don't know what an RPG video game is.
I don't disagree with the notion that RPGs should be allowed to portray both good and evil routes and have them have consequences, in fact, I enthusiastically agree (too much freedom ends up seriously trivialising a story, and RPGs usually tell those as well, it's not just a gratification simulator where every single choice is rewarded equally, that makes choices ironically meaningless. I recommend reading Larian's Adam Smith's take on it, it's very interesting because they want the routes to mean something).
HOWEVER... tackling the issue that's being discussed here: it's true that Tav's expressions during the kiss are removing the option for players to imagine how their Tav would react, which is also one of the charms of RPGs. It's early into that relationship, maybe they're into it, maybe they're just a bit nuts (lots of Durges playing that route) , but most importantly: this is a Tav that has gone through the kneeling scene and accepted it (which has similar elements) and is then asking for a kiss, perhaps several. A Tav in that situation could be scared, sure, perhaps it takes them by surprise, but I think usually they'd know what's going to happen.
I think what BG3 should do (well, in my opinion, it has done it since full release, but not everyone sees it that way) is to give you the tools to explore and reflect on that story and how that relationship would develop, not automatically assign the player character those emotions under circumstances that don't make a lot of sense. I don't think the sentiment is wrong, per se: Tav or at least the vast majority of Tavs would eventually realise that this wasn't a good bargain that they got themselves into, but this was handled clumsily. Also, I already said this in another thread, but sending out the message that this kind of relationship is harmful, while valid, doesn't mesh well with the fact that the kisses are set up as clear fanservice that's meant to be sexy. They should pick one or the other.
In Larian's defense, player character expressions are tricky. There were a few instances where my character made a face or a throwaway comment where I was like "He would not say that". I think sometimes you also have to ignore that and think "well, that wasn't canon". There's a lot of debate about whether or not PCs should be voiceless or voiced, so I guess it's up to the individual's preferences. If we want total and complete control over imagining what our Tav feels like, they'd have to have a constant serious face. I think a lot of the goofy animations where Tav's like crossing their arms are precisely the most default animations they could make. Truth is, we will never have full control over how the game itself depicts our character, we can never choose EXACTLY what our PC would say to people, and the kiss animations for basically every single companion are already assuming things: maybe my Tav wouldn't kiss Karlach like that, etc. So I understand that some limits have to be added, but Tav's face here had too much of a bias that I find at the very least preventable. I don't know if there was a good/perfect solution, but this one doesn't seem particularly coherent. I think some amount of railroading to better convey a story or its point is good, but there's a line that can be crossed where it takes you a bit out, or is perhaps a bit blunt/unsubtle.