Bug 19014 changed when autorenew notices for items with a hold on them was sent.  Some libraries have asked for the option to decide when those notices will be sent.  
For example:
Item is checked out on March 1 and has holds on it.  Autorenew set for 0, so patrons will get the no-renewal notice the day the item is due.
The library would like to send the no autorenew notice perhaps 5 days prior to the due date, independent of actually trying to renew the item.