The engine itself, I'm sure, still has those 4 ports. Technically, this design would be less restrictive imo since the 'collector' is part of the motor, there's probably nothing inside the 'collector' portion before hitting the giant hole flange piece. Which is why I don't see why people are getting all butt-hurt about there being no actual header.
Of course, this is all under the assumption that the 'collector' portion doesn't have holes the size of toothpicks. I'm sure it's not too bad, but I have never seen pics of inside it.