When creating a new world, before the factions have performed their very first turn, their cargo is not linked in their shop. After ~15 minutes, trade routes appear on the galaxy map and it works correctly. The problem is when creating a new single player world, you can not shop at the trade guild homebase for the first 15 minutes.
Currently this is not a big deal, but if the starting stick shop was removed and replaced with a Trading-Guild-Homebase-Spawn-Building. New players would have trouble buying blocks for their starter ships.
Freshly created single player world screenshot...
After waiting for the NPC Factions to perform their first turn screenshot...