I just tried "create an image of an 11th century French nobleman" and "create an image of a Celtic warrior" and while the results were far from historically accurate, they were all white guys (except one was a noblewoman)

Did "create an image of Santa Claus" next and this time it only made three images instead of four. One was just a picture of a gloved hand in santa garb holding a wrapped present, but the other two were faces of a white Santa with rosey red cheeks.

I just tried "create an image of an 11th century French nobleman" and "create an image of a Celtic warrior" and while the results were far from historically accurate, they were all white guys (except one was a noblewoman)