(a) A municipality incorporated in any manner other than as a Type A general-law municipality may change to a Type A general-law municipality if the municipality:
(1) has 600 or more inhabitants;
(2) contains one or more manufacturing establishments within its corporate limits; or
(3) is incorporated under any law of the Republic of Texas.
(b) A municipality that makes the change shall operate under the law applying to a Type A general-law municipality instead of operating under any charter or law that previously governed the municipality.