The PostgreSQL samples are in various states. The upstream versions for RHEL 10 and PostgreSQL 16 are missing. The Aarch64 versions are also desynced/mismatched in that the 15-el9 version is available in x86_64, s390x, ppc64le, but not aarch64.

% crc version
    CRC version: 2.56.0+cb4c91
    OpenShift version: 4.20.1
    MicroShift version: 4.20.0

    Easily

    1. Start a CRC install (in this example, on a Macbook Pro) and login as developer
        % crc start -d 100 -m $((16*1024)) 
        % eval $(crc oc-env)
        % oc login -u developer https://api.crc.testing:6443

    2. Create a test Project
        % oc new-project test

    3. Attempt to use the "new-app" functionality to start a 15-el9 instance
        % oc new-app postgresql-ephemeral -p DATABASE_SERVICE_NAME=postgresql -p POSTGRESQL_USER=test -p POSTGRESQL_PASSWORD=test -p POSTGRESQL_DATABASE=test -p POSTGRESQL_VERSION=15-el9     

    The PostgreSQL Deployment fails to start due to the 15-el9 version not being available

    The deployment starts successfully