Hi Bruce,
read here a good point to understand whether CentOS 8 could be a valid choice from a Moodle point of view.
Besides, there is a strong change in CentOS 8 policy starting from 2022, regardless what you will run on it: https://www.cyberciti.biz/linux-news/centos-linux-8-will-end-in-2021-and-shifts-focus-to-centos-stream/ .
More opportunities in https://www.redhat.com/en/blog/new-year-new-red-hat-enterprise-linux-programs-easier-ways-access-rhel .
HTH,
Matteo