Piter, it is the other way around. The Classic 2000 Sebenza is a re-release of the "original" design that Chris started with. In 1996 or 1997, they switched to a new design.
Responding to demands from customers, CRK came out with the "Classic". Yes, the blade isn't quite as beefy near the tip and the belly isn't as pronounced. I got the Classic Small Sebenza because I prefer the larger access to the thumbstud and I like the "look" of the slightly curved spine of the scales.
Good luck.