Rather than constrain the category because of confusion between it's historical and style traits, a new style should be created that accommodated both aspects of the beer together. I would call it an 10D American (Dark) Black Ale.
I'd personally like to see a sub-category for Specialty IPA, which covers Black, Rye and Belgian-American style AIPA/DIPA, as well as possibly "Imperial Amber" and "Imperial Brown" ales.