As stated by others, Craftworlds are already a thing, though right now they should still be exploration and long range trading vessels/fleets.We're before the Fall of the Eldar and Birth of Slaanesh, Craftworlds aren't really that big a thing and I'm not sure Exodites as we'd recognize them exist yet.
The Exodites left the core worlds a long time ago. They saw the decadence enveloping the Eldar Empire and went luddite in response (effectively) and left for Maiden worlds to settle into a frontier life style to live away from temptation.
With the Warp stirring the doomsayers should be out in full force in the Eldar Empire core and those that heed them will be starting to/in the process of leaving the Eldar worlds, some fleeing to the Exodite worlds and some flooding into the long range exploration/trading fleets that would eventually become the craftworlds as we know them.
In fact there are many, many more Craftworlds/proto-Craftworlds that exist in this period than in 30k/40k proper because many proto-craftworlds returned home to attempt to evacuate more people before doom befell the Eldar. Many didn't manage to leave soon enough to not get caught up in the Fall as Slaanesh's birth creates the Eye of Terror. Many proto-craftworlds would get caught up in the Eye of Terror and would be consumed immediately or suffer the same fate as Ulthwe. Getting caught in the pull of the Eye of Terror unable to escape, yet not be immediately consumed, resulting in a siege situation as Chaos forces regularly attack them.