A sovereign act of forgiveness for past acts, granted by a government to all persons (or to certain classes of persons) who have been guilty of crime or delict, generally political offenses, - treason, sedition, rebellion, draft evasion, - and often conditioned upon their return to obedience and duty within a prescribed time. The 1986 Immigration Reform and Control Act provided amnesty for many undocumented aliens already present in the country.
Included in the concept of pardon is "amnesty," which is similar in all respects to a full pardon, insofar as when it is granted both the crime and punishment are abrogated; however, unlike pardons, an amnesty usually refers to a class of individuals irrespective of individual situations. State v. Morris, 55 Ohio St.2d 101, 9 O.O.3d 92, 378 N.E.2d 708, 711.
Even your definition agrees with my point. It isn't an amnesty, because the punishment is not abrogated, but rather it is reduced or simply changed.
Thanks for proving me right.