Any incorporated city or town may become a noncharter code city in accordance with, and be governed by, the provisions of this title relating to noncharter code cities and may select one of the plans of government authorized by this title. A city or town adopting and organizing under the optional municipal code shall not be deemed to have reorganized and to have abandoned its existing general plan of government, upon changing classification and becoming a noncharter code city, solely because organizing under a plan of government authorized in this title changes the number of elective offices or changes the terms thereof, or because an office becomes appointive rather than elective, or because that city or town has come under the optional municipal code, or because of any combination of these factors.