The whole 'open-world' thing with MGSV has always been misleading, imo.
It was clear that the game's story is mission-based first-and-foremost, with the open-world thing secondary as more of a game level component, rather than a narrative driver.
Exactly why I'm so hyped. MGSV has the perfect "open world" approach. The game gives you so many options and you can be so creative in completing your objective. When you look at other open world games, you have one gigantic map where you can get lost in, but when you do the missions they are always very linear and you can only finish the mission in 1 way. MGSV really gives you freedom when it comes to the missions.
This game is going to be incredible.