There's actually a few Systems controlled by unfettered/pirate factions.
And not few of them have a high Influence with a blue Trend indicator - so it seems People with the proper preferences are already intentionally pushing those into Expansion.
May take a while, but if not countered - you might see entire Clusters of exactly such Systems slowly forming.
And why not... Pirates need a "safe haven" they can call home, too
PS.
Erishiko System seems a prime example that I'm aware of, although technically it's just a fairly good trade hub just like many others - thus automatically pushing the Faction controlling the prime trade Station into higher levels and eventually expansion.