Which version of Oracle are you using? And what is the archivelog deletion policy configured to? (do a 'show all' within the RMAN prompt)
Also, found something on metalink, Doc ID 1380368.1. Is your LOG_ARCHIVE_DEST_n still set? Outlined in the doc it says that even if the status is deferred, Oracle still considers the standby as still existing and will not allow for the deletion of archivelogs so that they can be applied to the standby. Looks like you'll have to unset the parameter or set the hidden parameter mentioned in the article.
If you are using Archivelo deletion policy on RMAN configuration, then you can clear as below:
CONFIGURE ARCHIVELOG DELETION POLICY TO NONE;
and please check How to safely remove a Data Guard Broker configuration? http://www.mahir-quluzade.com/2012/07/oracle-data-guard-11g-how-to-safely.html
Mahir M. Quluzade