It appears as if the zoo has been granted AZA accreditation for another 5 years. I can't find much about it other than a blurb explaining the AZA accreditation process on the zoos website.
"Accreditation by the Association of Zoos and Aquariums (AZA): “Accreditation” means official recognition and approval of a zoo or aquarium by a group of experts. These experts, called the AZA Accreditation Commission, carefully examine each zoo or aquarium that applies for AZA membership. Only those zoos and aquariums that meet the high standards of the commission can become members of AZA. AZA’s high standards for accreditation are constantly evolving and being raised. Around 236 zoos and aquariums, fewer than 10% of the approximately 2,800 animal exhibitors licensed by the United States Department of Agriculture, are AZA accredited. The Potawatomi Zoo has been continually accredited since 1987. The Zoo received its most recent five-year accreditation in September 2019."