These prequel chapters explained Anam (Mana)'s origin, but I'm more interested in that boy Mamoru, her last Earth companion in that alien planet. So would he become a God in his own artificial earth, or live a normal life, grow and die in that world?
Anyway, I think this was a perfect closure to the main story arc. There was not much remaining plot to expand the story upon, and since the author is busy with his new successful sport manga, unlikely he will return to create a new As The Gods Will manga series any time soon.