N.J. Stat. Ann. § 40:69A-208.2

Any municipality having adopted, prior to the effective date of this amendatory and supplementary act, a charter encompassing a council-manager plan of government heretofore authorized pursuant to P.L.1950, c. 210 shall continue to be governed, after the effective date of this act, by the charter and plan of government so adopted, until such time as the charter is abandoned or altered pursuant to article 1 of that act (C. 40:69A-1 through 40:69A-25), or amended pursuant to section 7 of this amendatory and supplementary act. During such time as the municipality shall continue to be governed by that charter, any provisions of, or supplements to, P.L.1950, c. 210 enacted or amended after the effective date of this amendatory and supplementary act, which would have pertained to that charter if the provisions of this amendatory and supplementary act had not been enacted, shall pertain to that charter and govern that municipality.