Sorry I wasn't clearer. Yeah its basically said that the Malalorians create or discover cloning technology and put it to use. When they're killed off, the secret to their rapid method of cloning largely dies with them.
Truth be told the Emperor getting a hold of it in some form is really more of a "Dark Empire" shout out than a critical plot point. I'm considering dropping it and just sticking with the above point about the technology was simply lost.