If I had to guess, there's some logic in there to make sure that the slave ship doesn't spawn too close to the station giving the quest, or the gate it's making for...but this seems excessive.
Other, probably-not-bug things I want to mention for amusement's sake if nothing else: literally every single Huari fortress I've found is in this system (which is also the Cyclops Corporation system). Several of them spawned within shooting distance of the Dwarg, who they are hostile to.
What's worse though is that *this* is where they put the Huaramarca gate!
It's *not* outside the system, and in fact is within spitting distance of the Sung Citadel IN JIANG'S STAR! :D