Just putting this out there because I remembered it, but I seem to recall somewhere that there are dark systems that don't show up on the galactic map. You can apparently reach them if your hyperdrive malfunctions. Apparently these systems can exist even in the midst of civilized space and nobody knows they are there. It's reasonable to believe this as well - some star types are so cool they wouldn't be visible even from the next star system over. It can sometimes be hard enough to spot brown dwarfs with your eye even within the same system. If these systems are real, maybe we've underestimated FD's ability to hide stuff under our noses. Can anyone confirm these systems exist? I think if these systems existed, finding them and charting them would add another interesting dimension to exploration.
Given the quantity of stuff listed in the DDF that is missing, there is no reason to think such thing is in the game. WYSIWYG