In the first Metal Gear, Snake kills the doppelganger (aka 'Phantom' Snake) and in Metal Gear 2 he kills the real Big Boss. It was a leftfield twist but one that explains how Snake kills Big Boss twice in the Metal Gear games. Metal Gear Solid V ended with the revelation that you hadn’t been playing as Big Boss, but as a man who had been brainwashed and surgically altered to think and look like he was Big Boss. It is, after all, like it or not, where Konami can make its money with microtransactions. Any sequel would surely expand on Metal Gear Online.
Konami invested a lot of resources into Metal Gear Online, it was one part of Metal Gear Solid V that continued to be updated after the game’s release - even where there were obvious gaps in the game’s single player that could be plugged.
