I was honestly surprised by the smiling for the kneel too. I had given feedback for neutral faces, and the first preview we got was fairly neutral. If the smile during the kneel is what bothers people, I wouldn't mind losing that. But I also play fairly stoic characters so grinning would never be my PC's face to begin with. So just not having the kneel smile would be a fine compromise.
I don't agree with it being a choice unless every companion gets a choice. Given expressions have changed for a lot of things. Even just Astarion's. It wouldn't be fair to give that just to Astarion and not, say, DJ Shadowheart and Minthara. But also, quiet honestly, I think they should just leave Astarion alone at this point. All the discourse is wearing out the fandom imo. Just my take!