Every annexation undertaken by the City of Guntersville prior to September 1, 2015, under any statutory procedure for annexation by the municipality and which annexation has been completed, notwithstanding any irregularity or defect in the annexation, either substantively or procedurally, is ratified, confirmed, and given effect in all respects. This section shall not apply to the annexation of any specific property which annexation has, prior to September 1, 2015, been held invalid by final judgment of a court of law of the State of Alabama identifying the specific property by legal description and date of annexation nor to the annexation of any specific property identified by legal description and date of annexation, the validity of which is an issue in a pending action commenced prior to September 1, 2015.