Whenever there is a consolidation of government as authorized under the Constitution of this State, the rights of and restrictions on electric suppliers as provided for in § 58-27-620 shall apply to areas within the corporate limits of a municipality being merged into a consolidated political subdivision except a municipality owning and operating a municipal electric system and shall be established as of the date of consolidation rather than on July 1, 1969, as provided for in § 58-27-620. On the date of such consolidations the same rights granted to and restrictions imposed upon other electric suppliers shall be granted to and imposed upon existing municipal systems as to areas within the consolidated political subdivision but outside the previously existing corporate limits of the municipality owning and operating such a system.