Unless Klingons can grow hair and this particular sect removed it for religious reasons. Hair is not out of line with those ridges being sensory organs, as they may be more sensitive and require protection that hair would allow.It's set in the Prime Timeline imo. But the biggest issue for me at the moment is how to bring the Legend of Kahless forging the first Bathleth from a lock of his hair in line with the new hairless appearance of the Klingons.