Don't worry the govt has not decided to impose the death penalty for those who lost their work ethics and try to retire. MM Lee was just expressing his opinion that retirement can result in early death due to a sedatary lifestyle. Now you know why the PAP govt keeps telling you to work harder and longer ...they are trying to prevent you from dying early. See how kind they are...they are very concerned about your longevity.
Now all the policies related to postponing your CPF withdrawal age, locking your CPF minimum sum up at a low (negative if adjusted for inflation) return of 3.5%, elimination of pension schemes for civil servants (but not ministers/MPs), etc are there to make sure that you won't be able to retire early and die prematurely. See how caring the PAP govt is? Although the huge reserves they accumulated over the years from Singaporeans can be returned to elderly citizens to help them cope with old age, they won't do it...its for your own good that you work harder and retire later to avoid early death.