First of all, I don't think that the Ocampa were killed or enslaved by the Kazon. As we all know, the Caretaker did stock them up with five years of energy and also sealed the holes which the Kazon could have used to get access to the underground city. According to the book "Caretaker" by LA. Graf (which is based on the script for the pilot episode) the Caretaker also downloaded all his knowledge to the Ocampa before he died. With that knowledge and all resources, I'm sure that the Ocampa did use all that to stay alive and develope, maybe constructing some weapons or starting to develope their powers again so that it would be impossible for the Kazon to attack them. The lack of water which the Kazon was suffering from has made me believe that the Kazon-Ogla on the planet were unde a siege from some other Kazon sects, otherwise they would just have to take a ship and find the nearest block of ice to create water of, or to go to the nearest system in order to get water. So it's possible that they would have their hands full with fighting other sects as well. Besides that, the Kazon had very little patience. They wouldn't sit around for five years or so, they would be bored and maybe leave long before that. We can also assume that the Ocampa on the planet may get some help from their relatives on Suspiria's array after they've been told about the current situation by the Voyager crew. As for Kes becoming the new Caretaker, I have to disagree. Her "super-powers" were silly and unrealistic from the start. That mumbo-jumbo was used only to write her off as soon as possible and it was highly unrealistic. Besides that, Kes wanted to go with the Voyager crew to Earth. She wanted to learn and explore and had no intention to return to Ocampa. Returning Kes to Ocampa would also definitely close all doors for a Kes come-back in upcoming books. No author would write any story about her life on Ocampa because it's too far away from Federation space where most of the action in the books are located. In stead they should use the following scenario: Kes is turned into an energy-being, restored back to normal by Q or Suspiria, arrives to the Alpha Quadrant and becomes a prominent factor in upcoming Voyager books.