The only time I had bearding on a black fabric project was when I used a white poly batt. I have made quite a few dark/black projects since, using regular Warm and Natural with no bearding.
I have only once used a black batt, it was purchased by my Sis and it was fine, but I think it was poly. It was used in a quilt with bright yellow and black... and it really didn't shadow black through the yellow, as I thought it might.