I can't think of any reason that Nazarbayev would do this unless he is considering stepping down as President of Kazakhstan. He doesn't need to be designated member of the security council as long as he is sitting in the President's chair. This appointment for life would only come into play if Nazarbayev is no longer President while he is still alive. As far as I can tell, it's the first time he has made any meaningful move against the idea of remaining president for life.
