Another interesting thing is the search function on the map knows of alternate names at least in some cases. Found out when looking for all the stars in the southern cross constellation.
Oh yes, every named planet has a procedural name they can still be found by. When the Colonia planets were renamed I still had old bookmarks with the old system names and could still find them using the old procedural name. Stars in the HIP catalogue can often be found by searching on more than 3 names. For instance HIP 65936 can also be found searching on HD 117440 and HR 5089, but it's actual name on the galaxy map is "D Cen", and it probably also has a procedural name hidden away somewhere.
It's just a relational database and they just set one of various names as the display name, the rest are assigned but not visible to the player but still searchable.