That's a great question Paul. I would think the creativity would emerge as soon as they can manipulate things. Then comes the hard part, protecting them from the judgements and fears that feed the lizard brain. Hopefully, some solutions will come-out of this challenge.
It does sound contradictory in this presentation, but having followed him for a long time, I think Seth is challenging the idea of the preciousness of being a "Creative", with the activity of doing creative work, which we can all do as we focus on "shipping".
I absolutely find that there are times when I have to struggle with the lizard brain to be creative. What I often struggle with is an image in my head of what my work should look like if it was perfect. But that is never productive, and that perfect image doesn't really inform the final product.