eeeeeeeh.
I think death/tech death is where the blues influence starts being more vestigial, and it starts borrowing more from classical. Even Polka (what is a blastbeat but a fast polka beat?) Are the diminished scales really from blues? Do the blues musicians play straight 32nd notes the way classical musicians do?
From an evolutionary standpoint, it definately does, since blues to rock to sabbath to metal, but death metal onwards really feels distinct. Especially symphonic.