I mostly agree, but you're idea of deathcore is different from mine. Whitechapel, All Shall Perish, The Acacia Strain, Suicide Silence and quite a few other bands are still deathcore (and still popular). Job For A Cowboy is one of the few deathcore bands that actually got out of the genre (and have been out for quite some time). Whitechapel's sound has a changed a bit, but that still doesn't mean they aren't deathcore (The others I mentioned really haven't changed much at all). I don't think deathcore is dead, I just think your definition of deathcore (scene haircuts, breakdowns every 2 seconds) is dead. The songwriting has gotten better and the genre has evolved, it isn't dead.
A few things you were way off on though:
1. The Red Chord was never deathcore, they have been deathgrind with minimal core undertones from the beginning.
2.There is a deathcore band on Summer Slaughter and that would be Veil of Maya. I don't care how many times you say it Sumeriancore isn't a real genre (neither is Ikeacore (This one is especially retarded) or Easycore for that matter.)
3.The Acacia Strain has always had heavy hardcore influences, but they are still deathcore. It's kind of like Despised Icon when they were still active, they are the epitome of the actual definition of deathcore: death metal/hardcore hybrid.
4.Molotov Solution has played a show in the past two years: I've seen them twice in the past two years and they played at NEMHF in April. They just broke up a few weeks ago though.