And on that note, most bands we all like are 'avant-garde' or 'progressive'. Deicide progressed on what Slayer did, Suffocation progressed from what Deicide did, Devourment progressed from that...too vague of a title. Like 'viking' metal. It's typically death or black metal with melody that sings about vikings. Gay. It's still death or black metal.
Progressive more has to do with bands progressing to me not the influences from other bands. Deicide,Slayer and Devourment,etc.. are not progressive musicians or bands. If you put it that way any band who formed would be progressive.