Is this change really so dramatic for pre-prod use? It sounds like centos will still be around although as the upstream of RHEL, which I interpret to mean less

Is this change really so dramatic for pre-prod use? It sounds like centos will still be around although as the upstream of RHEL, which I interpret to mean less tested or stable. But as far as compatibility between it and RHEL, shouldn't that improve? Why isn't this good enough?