Except you don't know how much of the content is being added, nor whether it was "cut" from development or not. I glitched into the Jovian Complex and the Terminus, and it looked like crap. No enemies, textures half-loading, plenty of areas where you could just fall out of the map... They have likely been adding placeholders to the game since it's release in preparation for the unfinished expansions. This way, less data needs to be downloaded and added once the expansion is released. Less data to download = less stress on servers = fewer players unable to download the expansion.