I'm not sure if new terminology will work on its own. (Maybe it will, like a shibboleth. Shine on, you crazy Jews.)
Perhaps we should drop the "metal" part of it? This should seed more creativity than just appending an adjective or noun in front of the word "metal."
"metal" hasn't been as tired as appending the -core prefix to everything (skacore, deathcore, metalcore, folkcore, rapcore), but we should give it a shot. Neoclassical sounds good enough to categorize the good music into, but that works only as an umbrella term.
I like the sound that the term "death grind" or "deathgrind" has, because it drops the terms "metal" and "-core", but the term can still imply grindcore with death metal influence, like the band Blood. "Thrash", as a unique standalone term, has a similar independent definition. Yet, as we know, the media re-dubbed it "thrash metal." Regardless, we still recognize that thrash, despite that it's just a single word, implies music which drew influence from hardcore punk and speed metal, and there are no redundant descriptors like "metal" or "-core."