I'm into the idea that xc\ racing position is more towards a road position, the narrow bar is is also a areodynamic position.

It seems to me that the majority of xc is @$$ on the seat, straight bar hands lower position. It needs to be balanced with how wide your chest\ arms are.

Xc is 'to me' more an endurace\ distance \ breathing riding style. It is more similar to road riding hence the flats, drops >narrower bars.

That looks to me to be a sit down racer.

As you narrow the bars, it 'seems' to make the stem feel out further. It positions your torso a bit back.