I wouldn't retire the media then delete it, otherwise (as stated) if you need to use it you'll have to inventory it and catalog it.
You could simply create a media set for year-end backups (with a REALLY long overwrite protection period), and add a Vault. Then make sure the year-end backup assigns the media to the new media set, then move the tapes to the vault, both in the software and in real-life.
That way you can report on what media are in the vault, and if you need to restore, then the data is in the catalog (depending upon your catalog settings),