edit: To clarify, I think AI is the wrong question it's a question of the layers of abstraction and where it puts you in the labor force. Who cares what inhuman force is telling you what to do or how fast to do it?
I assume there will be no clear definition of where the API begins and where it ends when this happens. The various systems which employ humans will probably be mixture of AI and humans working together through multiple interfaces.
http://rein.pk/replacing-middle-management-with-apis/
edit: To clarify, I think AI is the wrong question it's a question of the layers of abstraction and where it puts you in the labor force. Who cares what inhuman force is telling you what to do or how fast to do it?