Notwithstanding any provision of the general statutes or any special act, charter or ordinance, all acts and proceedings of the officers and officials of a municipality pertaining to the treatment as taxable or not taxable, as the case may be, by the municipality of any real or personal property held by, or held in trust for, a health system, as defined in section 19a-508c, on its October 1, 2014, grand list or earlier grand list, are validated and the municipality shall continue to treat such real or personal property as taxable or not taxable, as the case may be, in subsequent tax years.