They are indeed created by the backers, but they were created using a version of the character creation system that was then heavily revamped three times over. I assume that the developers made minor tweaks to try to keep them in line with the new character creation systems, but little more than that.
At the very least, I'd assume that the folks who backed high enough to create them might want to submit some alterations using the post-release character creation system.
Oh, and Tracek - Cain is available with all the other Henchies, in the Hall of Heroes at the End of Time.
