The wireless flash control isn't there because of the flash so it's impossible for it to be in the Mark IV. It was released to counter the D3s. That's what competition is. What was the original D3 released for? Nikon wanted to counter the long-standing 1-series love in the professional market.
It's not an N at all. It's an upgrade over the Mark III. Consider the Mark IIN against the Mark II. They only released the Mark IIN because of small technological advances that they could add to the Mark II as it was, such as the LCD and the ability to write RAW to CF and JPEG to SD. The Mark IV isn't just a Mark III with small technological advances like that. It's a new beast. Not to forget that the normal differences still apply. The Mark IV has another new AF system (you can see it at Canon Mark IV video review: http://www.infoborder.com/Digital_Cameras/Video/CanonEOS-1DMarkIV.php ), so it's going to be even stronger than the 7D in that area.