If rc.local is for local configuration, why is there any code in the default implementation? The code to create /etc/issue should be moved to a separate initscript to simplify upgrades when rc.local has been customized. The default rc.local should be empty of anything but comments.
Its for local use and customisation. It contains some initial customisables. Its common to customise the rc.local to append things like 'Property of Foo Bar Corp, phone ... if offered for Sale" and the like as an example