We like and use this - similar, actually - both in LEO training and as part of what we do in my art, both as part of an Iron Wall, and in defeating multiple opponents.
I don't particularly like the second arm as part of it though. And I prefer the elbowing arm in a different position, I won't cup my hand behind my neck, we use the hand/palm beside the ear, it makes the attacking elbow longer by several inches. It also allows the hand to be more active reflex or follow up wise.
The problem with the video clip, in my opinion, is it's only shown slowly. There's no real demonstration to how a blitz changes the dynamics of what the opponent can do. And when doing it, it's a full on blitz forward.
"Iron Wall" as we call it, and I don't remember where that term originally came from, consists of that elbow position, the opposite knee coming up the middle as a strike, the opposite hand in a palm heel strike/push to the front of the ribs, and the head lowered into a head butt. The time - is the same time frame as any forward step/blitz, that is One Beat. It is used to enter, to get into the kitchen. [as we used to say]
I love using this wall against an opponent who's raining punch combinations, or thinks he's going to. You have to gear up to properly to train it, though. Motorcycle helmets with a face shield are good, and safety kick head gear for the blitzer for the head butt part of it.
It's my favorite entry. I love entries.
As for "can't the opponent do this or that?" Yes. That's why it's called a fight.
