Cut content from MGSV: The Phantom Pain Abound
It's no secret that there's some missing plot points in MGSV, but it looks like more and more cut content is surfacing. Though, some have said it isn't cut, but simply not yet achieved, we have not seen it in game. Regardless, this content has been surfacing on YouTube, with fully-voice acted and motion captured cutscenes showing things that are hard to fit into place with the overall story. This article will contain numerous spoilers for MGSV: The Phantom Pain, so if you haven't finished the game's story, please go no further than this Chicken Hat.
Now, if you beat the game, you'll remember that Eli, Psycho Mantis, and the Child Soldiers make off with Sahelanthropus after adjustments are made to make it functional. Eli and the children take a helicopter pilot hostage and leave Mother Base, never to be heard from again. In this official Kojima Productions video, we are shown Mission 51, Kingdom of the Flies, in which Snake infiltrates a small island, where Eli and the children are hiding. Snake has to infiltrate the island avoiding traps set up by the children, as well as XOF agents who want to get Sahelanthropus. Big Boss would engage in a climactic battle with the Metal Gear, piloted by Eli and assisted by Psycho Mantis. You can see portions of the cutscenes and concept art for the mission.
As people began digging into Phantom Pain's files, a monologue by Big Boss was found and put on YouTube, but Konami quickly took it down. A few days later a new cutscene was shown, in which Miller spoke about the total Nuclear disarmament of the world, with some Child Soldiers present, leading people to believe this was more cut content. However, Online Community Manager for Metal Gear, Robert Peeler, says that the cutscene is achievable in game, but gave no more than that.