Maybe you use a simple rule for this like ...

The email has already made it into Retain, I want to remove them from Retain.  We keep email for 15yrs.  Our old archiving software had this ability and after 2 years we have 60k+ of these unneeded 'notification' email in our archive that I would like to delete.  It looks like I could do it through the advanced search as the admin, but I do not want to have to remember to do it every so often, I would like to just put it on a schedule and forget about it :-)  I have a 15yr rolling purge setup to run once a week for everything else.

First of all I would try to avoid to archive this kind of mails in future. So you have to adjust your retain profile.

Did  you try to search for mails from this sender, then select all (all pages!) and delete?

I am still learning Retain, I found the Advanced option tab on the profile and added a 'Sender is not' rule with the full noreply email address.  I will check tomorrow morning to see if this removes them from being archived.  (looks like it should)  I have also run a delete by the sender email from all pages on the search messages.