Your ride has an alternator controlled externally by the BCM via the IPDM, it doesn't use internal regulation. Those "smart" external systems are infamous for stupid behavior that ruins batteries from chronic under-charging. If the alternator has low output and not no output, they need to check it.
Not that the alternator couldn't have gone bad, the sort of bushings used in alternator construction are usually just as unhappy with disuse as lots of use. With 5K miles a year, you may find issues with various other seals and bearings as time goes on.