Without writers taking creative freedom, we wouldn't have Korriban. It was invented by the authors of Tales of the Jedi: Dark Lords of the SIth in 1995-96. That comic book also introduced the Cathar and the series as a whole gave us Onderon, Dxun, Miraluka, Sith Purebloods, Ossus, re-introduced the Mandalorians (who hadn't been used since the 1980's) and gave us a first look into ancient Sith culture.
And without that comic book series, we wouldn't have this game. Bioware expanded on that series and gave us Taris, Manaan and Lehon. Now they have created Denova, Makeb, Quesh, Cademimu, Athiss and expanded upon the Voss, who previously were largely unknown. Dromund Kaas was created for the game Mysteries of the Sith.
I think it's more interesting to add new lore than simply rehashing everything all the time. Keeps things fresh.
I would have to agree. This is where Star Wars lives, not the movies. I'm more interested in what the OP had to say about Kolto.