As discussed with idl0r: I stumbled across the warning "/etc/conf.d/local should be removed". The same should be done for /etc/conf.d/rc.
I would vote for closing this as wontfix for the following reasons: 1) /etc/conf.d/rc is never used in openrc, and 2) the migration guide specifically instructs you to remove this file after you migrate the settings.
Looking at this further, there is already a warning in the openrc ebuild for this in pkg_preinst. This is a migration issue, so I don't think the warning should go in the openrc code base.
I just ran the following test as root: touch /etc/conf.d/rc emerge -1 openrc This gives a warning in the emerge output about migrating /etc/conf.d/rc to /etc/rc.conf and removing the file, so I think we are covered for this bug. If no one disagrees, I will close this bug as invalid.
After researching this further, I think invalid is a better resolution because: 1) the openrc ebuilds have warnings about removing this file as shown above. 2) Openrc never supported /etc/conf.d/rc, so if we add this to the code base, we would be adding support for a file just to warn about it.