It's obvious they're trying to prevent piracy by...making them wait two weeks I guess? If they weren't going to buy the game on PC, they are not going to buy a console + game just for it. The MGS fans and people interested in the product were already going to buy it day one, so I really don't see who Konami is trying to sweep with this move.
Maybe it was a deal with Sony and MS to maximize console profits?
That at least seems more believable than piracy, maybe not an actual deal but just to maximize sales on the consoles in general. People who pirate games may have not even bought the games they pirate in the first place.