Donna Burke, iDroid voice actor for MGS 5, has confirmed that Kojima is set to leave Konami.
This article is accurate. However be assured that MGSV has been made, it is ground breaking, breath taking in its… http://t.co/Rej0eTdEMq
— Donna Burke (@db_singer_actor) April 10, 2015
Donna pointed to this article by GameSpot, which hint at power struggles and Kojima planning to leave Konami shortly after The Phantom Pain gets released.
Donna also assures fans that the game is essentially finished and is just receiving some polish prior to release.