I'm not sure what do you mean? DOS features isometric camera and PoV for the viewer/player, you can't really see aspects of their expressions and emotions. Unless you are talking about character portrait during dialogs? Like in jRPG/visual novel games - the tone of the dialogs/sentence being reflected/supported by one-moment emotion?
Yes, the character portrait during dialogue. The expression on the 3D model isn't likely to be seen and doesn't matter much.
The previews for this game suggest that dialogue with the other character is frequent and that will also affect the ending, which is why I think different expressions would help connect the player to the characters they control better.
