Hi,
we are using Katello for patching of few OL 7 servers. Due to lack of other options, we are using the same method as described in that issue. It’s no beautiful solution, but at least it works for now. Oracle explicitly obsoleting subscription-manager in their rhn builds is quite a pain though to get it working initially.
If you needs some tips, I’ll gladly help out once I’m back in office on tuesday.
In the current situation, whether there will be subscription-manager for OL8 is probably up to dgoodwin (unless someone here takes up the task).
Regards