Upcoming RHEL 9.y releases are not usable for testing until the version is officially released. That's primarily because dependency repos are a locked behind the VPN, which isn't accessible from the CI.

It'd be good to get ahead of the RHEL 9.y release tempo so we can verify MicroShift on the platform prior to it's release.  Centos-Stream-9 contains the same bits that MicroShift depends on as RHEL9, and is available prior to the RHEL release.

It's worth taking time to see if Centos can be used as an early detection platform for MicroShift.