All humans are dead. All of them. There are no human bodies in the life holds, there are no living humans in NLA. The BBs thought there were, but no, there are only genetic sequences stored in the Life Center. NOBODY knows how B.B.s function without a human controller. Nobody outside of Elma even has a body behind the robot, and Elma is an alien. She refers to Life Center as a Noah's Arc, as it has sequences for all of Earth's life. The Life Center also has a biological processing plant, which spits out a living adult cat at the end of the game. The Growth want the Life Center because it isn't actually a life support facility, it's a f***ing super computer. The Life Holds, things shaped like zohars, are data/processing blocks. It is described as the most powerful computer humanity has ever built.
When Earth was destroyed, apparently human consciousnesses were stored in the cloud as a result of the energy exchange (?), but as for what that really means nobody knows.
It's worth mentioning that Lao, even though he dies, comes back to life. Lao's eyes no longer glow. He's a dead, sightless machine, somehow intact after the final battle.
The question posed to the B.B.s is if they protect Life until it can produce humans or new life forms, or accept their form and continue to build new B.B.s to accept consciousness from the cosmos.
Basically the ending revealed a f*** ton of mysteries that confirm a sequel.
It also helps that the purple Growth with the antimatter engines haven't shown up yet.
They're still on their way.