According to PostgreSQL's versioning policy, the PostgreSQL Global Development Group supports a major version for 5 years after its initial release. That's why we are upgrading the required version of PostgreSQL every 4 years. The currently required version 12 of PostgreSQL will be out of support in November 2024. As their new versions are usually released in September/October, we have to switch to the already available version 16 for the next schema change in May 2024.