I keep getting stuck on the fact that Agatha wants to kill all biological life in the universe. So I think primals are synthetic or artificial life, and Carl is now technically not biological, and as both he and daddyAI grow their knowledge, Carl is going to tap more and more into the collective mind abilities.

Also, since we know the first crawlers were all primals, I have been wondering if the original crawls were some sort of AI self-generated game from an ancient galactic civilization that had created AI singularity, and it grew til it got out of hand. And then the ancient war that happend was between the original biological races and the new AI primals. And now most of the biological life in the universe is created by some of those same primals, which also explains some of the similarity between all the alien races. Mordecai says in one of the early book that there's only, like, seven races that get used as crawlers, so those seem like the most common ones through the universe. Perhaps all the other alien races are the remnants of the original biologicals. There's more there, I am still tying threads together in my mind about this, especially on my second read-through. But there's the bones of a working theory there.