you're probably thinking - but if it sounds new, then it's not Metal anymore !
so AKSHULLY there has been research into this and basically Metal music is defined by "spiky" mathematics. it's the same as what defines gothic Architecture or the font in your screen name.
so you can bend the genre quite a bit and still be unmistakably metal so long as the "spiky" mathematics are preserved ...
this "spikiness" is associated with things like fear, pain, aggression and so on ... also darkness ...
the opposite of this would be the smoothness and curviness of pinup dolls, cherubs etc ... also pink color ...
well obviously smarter people than me would be able to say more on the subject - i haven't even studied music theory. my point is merely that i see "Metal" as a wide field, that also should keep widening. whereas i imagine you you see it as a niche genre that should stay that way.
personally i think the latest and most cutting edge sound in music is "crunchy" sound, but that of course isn't metal and i will have to find ( or create ) some other community to put it in ...
and like i said you guys are more passionate than me about metal so what you want to see here is more important than what i want.
on other hand i will rule "GalaxyBrainDance" with an Iron Fist.
