I actually came by another dead body in the factory a little far apart from the place we found 2B's prologue body, but i am not too sure if it's 9S's body or another android's body, there's also a quest to find 11B body in the factory as well so i figured there should be more than one dead bodies lying around. It's near the switch where you can lower the bridge, and that room is pretty hidden by the walk path and camera angle, if you check the map there's a huge room behind the walk path above, where normally we would think it's a wall, just walk into it and you will come up at a room with a switch to lower the bridge connecting to the starting area (a short cut).. there will be a body near the corner of that room.