In a recent interview at the Tokyo Game Show, Kojima spoke more about the design of Metal Gear Solid V. When speaking about the fact that the game was open world, he reportedly said, "MGSV eliminates game design."
Kojima told reporters:
So the idea is pretty simple. "A certain person is located at this place," so you find them, rescue the person, and call in a helecopter so you can evacuate. That's the story. From a game design point of view, there aren't many moments that say "You must do this in this situation." In a real military base keys are located in vehicles, so the player can drive a care if they want, but nothing tells you "Get in a car and drive away." That's something players decide.
While the open world doesn't necessarily eliminate game design, it's interesting to see this perspective. Kojima also mentioned they did not want to mark locations, but stated, "It might be easier if they were there."
Along with game design, he also talked about missions that ran alongside the main missions and what he dubbed "dumb" missions. These "dumb" missions were designed for messing around and raising your ranking. Kojima noted that completing the main and side missions would slowly reveal the overarching storyline of MGSV.