That's the way a lot of people read the statements, and that's what wigged so many of them out. The idea that the cast would be completely changed, or even mostly changed unnerved many, probably including NBC execs, who may have ordered some changes which led to Kring taking an uninvolved stance in the show's writing. His five year plan went out of the window, and the show has been crappy ever since.
The plan was that there were going to be new central characters, and many of the current central characters would become peripheral characters. The Peters, Hiros, HRGs and Sylars were going to become the Haitians, Micahs, Angelas and Claudes. At least, the ones that survived. Every volume would be a new and different and exciting storyline. People would learn what had happened to their favorites, but the show would not center on them.
Claire was always supposed to be long term, Hayden was the only one that I know that had a five year contract. However, HRG, Sandra and Lyle were NOT so designed, and the removing Claire from the typical suburban lifestyle would have made her an interesting character, imho.
I made the mistake of trying to explain this on the 9thWonders message boards during the first few eps of season 2. Those guys tried to crucify me. How dare I say that Nathan and Matt should be dead? Ugh.