For the RPL feature The goals are to 
1) Disable the RHN yum plugins 
2) Remove the RHN system id
3) Disable the daemons
4) (Optional) add the --remove-rhn-packages

Rich, in implementation, I found the following packages for rhncfg-* (the implementation tries to remove these packages explicitly):
 - rhncfg
 - rhncfg-actions
 - rhncfg-client
 - rhncfg-management

We were wondering if customers ever create custom packages with the name "rhncfg-" and/or if the above list is complete (i.e. should we literally do the equivalent of `yum remove rhncfg-*`, instead of removing explicitly those packages listed above)?

customers can create custom packages with whatever name they'd like. I think the safer option is to remove them explicitly as 'yum remove rhncfg-*' may have undesired effects. 

The only rhncfg-* packages we ship are:

 - rhncfg-actions
 - rhncfg-client
 - rhncfg-management

Marking bug as verified

[root@rhel69-shwetha ~]# rhn-migrate-classic-to-rhsm --help | grep remove
  --remove-rhn-packages
                        remove legacy packages

Register to rhn:
-----------------------------
[root@rhel69-shwetha ~]# rhnreg_ks --username ******** --password ******


Verify status of rhnsd and osad deamons:
----------------------------------------------
[root@rhel69-shwetha ~]# service rhnsd status
rhnsd (pid  8162) is running...

[root@rhel69-shwetha ~]# service osad status
osad: unrecognized service

Check if following packages are installed:
--------------------------------------------------

[root@rhel69-shwetha ~]# for rpm in 'osad rhn-check rhn-client-tools rhncfg rhncfg-actions rhncfg-client rhncfg-management rhn-setup rhnpush rhnsd spacewalk-abrt spacewalk-oscap yum-rhn-plugin'; do rpm -q $rpm; done;
package osad is not installed
rhn-check-1.0.0.1-39.el6.noarch
rhn-client-tools-1.0.0.1-39.el6.noarch
package rhncfg is not installed
package rhncfg-actions is not installed
package rhncfg-client is not installed
package rhncfg-management is not installed
rhn-setup-1.0.0.1-39.el6.noarch
package rhnpush is not installed
rhnsd-4.9.3-5.el6.x86_64
package spacewalk-abrt is not installed
package spacewalk-oscap is not installed
yum-rhn-plugin-0.9.1-60.el6.noarch


Now try to migrate to rhsm using --remove-rhn-packages
---------------------------------------------------------

[root@rhel69-shwetha ~]# rhn-migrate-classic-to-rhsm --remove-rhn-packages Legacy username: qa
Legacy password: 
Retrieving existing legacy subscription information...

+-----------------------------------------------------+
System is currently subscribed to these legacy channels:
+-----------------------------------------------------+
rhel-x86_64-server-6

+-----------------------------------------------------+
Installing product certificates for these legacy channels:
+-----------------------------------------------------+
rhel-x86_64-server-6

Product certificates installed successfully to /etc/pki/product.

Preparing to unregister system from legacy server...
System successfully unregistered from legacy server.
Stopping and disabling legacy services...
osad: unrecognized service
osad: unrecognized service
Removing legacy packages...
No Match for argument: osad
No Match for argument: rhncfg
No Match for argument: rhncfg-actions
No Match for argument: rhncfg-client
No Match for argument: rhncfg-management
No Match for argument: rhnpush
No Match for argument: spacewalk-abrt
No Match for argument: spacewalk-oscap
warning: /etc/sysconfig/rhn/up2date saved as /etc/sysconfig/rhn/up2date.rpmsave

Attempting to register system to destination server...
Registering to: subscription.rhsm.redhat.com:443/subscription
The system has been registered with ID: 3b7edf8c-ed47-44f8-a9c4-6f03f21bf401 

Installed Product Current Status:
Product Name: Red Hat Enterprise Linux Server
Status:       Subscribed

System 'rhel69-shwetha' successfully registered.


Now verify if following packages are removed:
----------------------------------------------------

[root@rhel69-shwetha ~]# for rpm in 'osad rhn-check rhn-client-tools rhncfg rhncfg-actions rhncfg-client rhncfg-management rhn-setup rhnpush rhnsd spacewalk-abrt spacewalk-oscap yum-rhn-plugin'; do rpm -q $rpm; done;
package osad is not installed
package rhn-check is not installed
package rhn-client-tools is not installed
package rhncfg is not installed
package rhncfg-actions is not installed
package rhncfg-client is not installed
package rhncfg-management is not installed
package rhn-setup is not installed
package rhnpush is not installed
package rhnsd is not installed
package spacewalk-abrt is not installed
package spacewalk-oscap is not installed
package yum-rhn-plugin is not installed


Verify status of rhnsd deamon that was running earlier:

[root@rhel69-shwetha ~]# service rhnsd status
rhnsd: unrecognized service

[root@rhel69-shwetha ~]# rhn-migrate-classic-to-rhsm --remove-rhn-packages 
Could not find up2date_client.config module! Perhaps this script was already executed with --remove-rhn-packages?

Be aware that running rhn-migrate-classic-to-rhsm --remove-rhn-packages will also remove package subscription-manager-firstboot.  This is because subscription-manager-firstboot's dependency chain includes rhn-client-tools which is directly removed as verified in comment 8.


Additional Info:
[root@jsefler-rhel6 ~]# rpm -q --whatrequires rhn-setup
yum-rhn-plugin-0.9.1-60.el6.noarch
rhn-setup-gnome-1.0.0.1-39.el6.noarch
[root@jsefler-rhel6 ~]# rpm -q --whatrequires rhn-setup-gnome
subscription-manager-firstboot-1.18.4-1.el6.x86_64
[root@jsefler-rhel6 ~]#

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://rhn.redhat.com/errata/RHSA-2017-0698.html