Did some exploring to find profiles in these categories and Needs LNAB does seem to be useful for Black Heritage profiles. Other than those, several profiles seem to have a sourced LNAB so don't see why they are in that category.
Had trouble even finding the Unknowns category. Finally did a Google search to find it. Not many profiles, but one of them is an "I don't know" Is this a new one for your problems list or have you already seen it? I also use Wiki+ to find profiles to research Unknown last names, so see no need for that category.