They care about fulfilling the workstation support contracts. But if they can reduce the scope of what it means to support workstation support contracts, it is in their interest to do so.
They respond to X bugs right now because right now X is still in versions of RHEL they support. When that is no longer true, do you really expect them to continue supporting X on other distros?
Will they continue to do so, on company time, for packages that are no longer in any supported version of RHEL? I think they fix bugs that presently or will effect both Fedora and RHEL, or do more in their free time because they are themselves enthusiasts and not just corporate workers.
Dave Airlie the guy who maintains the AMD drivers works for Red Hat, on xorg and wayland and the KMS that both use.
Not including xorg in RHEL doesn't prevent people from running xorg on rhel. The question is, why would you ? Red Hat is aiming at the server market and the cloud, not the desktop.