Metal Gear Solid V may have a slightly more specific release window. A tweet from analyst analyst David Gibson indicates that Metal Gear Solid V: The Phantom Pain will not be available until the fiscal year ending March 2015. Gibson additionally states that “a prologue” – likely referring to Ground Zeroes – will launch in the fiscal year ending March 2014 “to keep interest going.”
How Gibson obtained this information is unclear. It’s possible that he got in contact with Konami on the specifics of Metal Gear Solid V, or it could be nothing more than a guess (though the way his tweet is worded doesn’t point in that direction).
Releasing Metal Gear Solid V’s parts separately would make sense given recent comments. While Ground Zeroes and Phantom Pain make up the entirety of Metal Gear Solid V, Konami has said that the two are “separate games”. Ground Zeroes is a much smaller portion of Metal Gear Solid V, and Hideo Kojima already confirmed that “Ground Zeroes will come first. It will kind of be Phantom Pain on a smaller scale.”