The vibe I get from it is "Content in which one can fail at accomplishing". Take, for example, a war between the three major factions in game. Such a war would begin by dev action, and end by dev action. There wouldn't be a clear winner, because a side actually winning and crushing another faction would seriously skew the game storyline in ways the devs wouldn't want to handle. In the end, you'd have a war, with a declared "winner", nothing really changed in the galaxy, and no real impact from the PCs playing in it.
Now take two player run factions duking it out. One side can legit actually win the battle. The actions of players DO have an impact in that storyline. You can hypothetically run the losers out of their space, after which they slink off and attempt to devise new ways to strike back."X defeats Y" isn't just a little RP blurb in the fiction, it's something that actually happened, with actual impact on the game.
Some see it differently, but that's how I feel player content beats dev content. Those who disagree actually want a game with the sort of "stability" a dev controlled static storyline gives. Elite has room to go in either direction, depending on the whims of FD.