I think you are spot on here. Watch Mallory on this play, he is in the same exact position he was on his TD catch where he faked the block. More importantly, when he actually does block on this play, his movement is very similar, makes it hard for the LB to tell when he's really blocking or releasing. He could easily release like he did on his TD catch and slip behind the defense if they collapse on Harley, or King can just keep it and hit Mallory straight up off of the PA. The formation has several options built into it.