He means to say that we are going to see how the Aliens became what they are,... Its pretty obvious that they are being bred to assist the SJ's in terraforming. I MEAN we all read this stuff in THE UNMENTIONABLE script.
The answer is waving around in front of you....
The man is NOT going to show us the ALIEN life cycle in a PREquel to one of the most influential classic SCI FI films of all time because that film would be worthless if you knew what the ALIEN's lifecycle was when you saw it.
Ive said this countless times and no one is willing to consider the weight of it. He cannot make this movie and reveal the Alien lifecycle as we know it. Not only is it run dry, as he said, but it will ruin his masterpiece. No one with a head on their shoulders would do that to there MOST influential creation.
Look at the HARVEST script, draft or not, that is what he means. Not necessarily the SMALLER versions, but the ORIGIN of what the ALIEN is, is what he means. That will be a new design.