I don't think this works simply because the distinction for black metal is in the fact that it was an artistic movement, that it was defined by those who were a part of it, and we can label it like a historical period. This leaves out the possibility of new black metal, and I personally think that this is fine.
Art needs more labels/terms. Please refer to my other thread on "The contradictions of black metal and terms" for a better understanding of what I mean by "terms". Black metal was an artistic movement, indeed. But, the problem is that everything is art (as proved in the "Dadaist" movement in the early 1900's). Everything is art, it's only a matter of whether you agree with it or not, and having more "terms" will helps us (the groups) know better what we agree with.
Once we can agree on terms, we can begin to agree and disagree on who is/was really a part of "black Metal".