I don't think the agressiveness is what makes the video crazy, honestly agressiveness wasn't THAT bad for minions unless you ran away from shit(basically there's a limited leash range around you and once minions go past it if you move in any direction, they'll leash back to you instead of killing shit, but otherwise they acted pretty agressive already in that radius). The big buff in that is zombies move at like 500%movespeed than what they used to. Like literally don't think you can get them to move them that fast currently on live with EVERY minion speed sources. Jewels, minion speed support(which is mostly garbage), queen's escape and whatever other uniques, and I still don't think they run that fast.
And like Deathwing said, they usually suck at displaying shit so that might not be a fully stacked setup. In fact in the Feeding Frenzy reveal, you can see a Zombie with just one support(I assume Frenzy since the letter doesn't exist atm) and the zombie has like +200%movespeed or some shit. That said in the gameplay vid, it seems the character has Queen's Escape, the 2H fated unique sword which gives 100%movespeed to minions, but is also a 2H sword with otherwise fairly garbage stats other than +1zombie +2skeletons. I assume they raised the base movespeed of minions a lot to make them feel less sluggish and more responsive, but that's a huge fucking buff to zombies/skeletons(which also seem to be getting Dash, the new movement skill, so they'll be better at moving from one pack to another).
The Deathmarked thing is also gonna be OP for bosses, since you'll basically be able to deathmark then run around without having half your minions cancelling attacks to follow you and shit. I assume/hope it has a limited range to ~1screen since otherwise you'll just offscreen bosses, but still.
That said for map clear, Soulwrest was already pretty fucking fast, I can't seem to find a good video but that shit with 2.4s convocation cd cleared real quick. Maybe I should make my own video.