There are several variables to your question but I will try to narrow it down.
If your truck is a 13 to 16 and already has the microphones in the mirror your current harness should support the Auto Dim and Auto High Beam features.
You will need to enable the correct codes in the BCM with the Alfa tool in order for it to work. The dealer cannot enable these codes.
If you have the RA 2 5" screen you may have an issue with the soft keys appearing on the screen to control them. I have added the Auto Dim feature to newer Rams with the 5" screen and the Soft Key for that feature did show up but I've never tried it on the 13 to 16 trucks. The controls for the Auto High beams is displayed in the settings menu on the RA3/RA4 8.4" radios and I'm really not sure if the RA2 radio is capable of showing that feature.
There are two different mirrors for Auto Dim only and Auto Dim/Auto High Beam. The Auto High Beam was only available on the Laramie or Sport.
If you want to add the rain sensing wipers you will need to replace the mirror harness plus purchase the actual rain sensor and the correct rain sensing windshield. You would also need to enable the codes with the Alfa tool and see if the controls for it show up if you have the RA2 radio. If you have already upgraded to the 8.4" radio you should be fine.
The Auto High Beam mirror has what looks like a small camera that detects oncoming traffic. This is a Auto Dim/Auto High Beam mirror. You can clearly see the lense.
Sent from my SM-G981U1 using Tapatalk