Every annexation heretofore undertaken under any statutory procedure for annexation, by the City of Cullman, Alabama, and which the annexation procedure has been completed, and notwithstanding any irregularity or defect in the procedure, shall be, and is hereby, ratified and confirmed and given effect in all respects as if all provisions of law relating to such annexation proceeding had been duly and legally complied with, but provided that this section shall not apply to any annexation or attempted annexation which, prior to May 29, 1984, has been held invalid by the Supreme Court of Alabama, or by the Court of Civil Appeals of Alabama, or by any final decree of the circuit court or other court of like jurisdiction in Cullman County and from which decree an appeal was not taken to the Supreme Court of Alabama or the Court of Civil Appeals of Alabama within the time provided by law for taking such appeals, or to any annexation, the validity of which is an issue in any pending suit commenced prior to May 29, 1984.