Why would you delete that folder? Just set all the repos to enabled=0 to disable the repositories that are created by packages and leave all the RHN-stuff in tact.
I usually run the following command in that folder: sed -i 's/enabled=1/enabled=0/' *.repo
If any RPM is updating the repo-files they usually don’t get overridden by the updated RPM, but the new file is put along side the modified repo-files with the extension .rpmnew added to it. That way yum won’t pick up the new files and all file-based repositories are disabled by the sed-command.