According to this How to install software or upgrade from an old unsupported release? question, EOL releases are archived to http://old-releases.ubuntu.com.
But currently, I cannot see Ubuntu 12.10 and Ubuntu 13.04 to be available on this website, while all others(since 4.10) are available, as you can see in the screenshot below
So has canonical and/or Ubuntu devel-teams decided not to archive EOL releases any more?
or is it work to be done?