It's been mentioned for a while now by players like LK. At least since last EVO and I remember some random tidbits about it before that.
It's by no means invincible, it's just another thing to bait for. But if they don't bait it they get wrecked. Also it's very execution intensive.
Now that I look at the inputs, even though I know it works, I don't understand: shouldn't putting 1A+B make for a TRM? You can put in 1A+B+C if you expect a throw next, but you already input A+B earlier.