Sometimes. I mean, would you be enjoying someone that is dancing with literally no emotion on their face and they look like a robot, or someone that is actually showing emotion while dancing
I agree with itsquinnbro. Apart of dancing would definitely be emotion and with that comes with facial expression. Your dancing should tell a story and you can't tell a story with no expression.
Another question, do most standard dances have a fixed expression? Fixed as not in unchanging, but more like facial expression that is usually used...