Thought I would update this thread.
Last night I checked UConnect and there was an update available. I have a 2016 with 8.4AN.
The new version is 16.09.09. I bit the bullet and downloaded the update and flashed it this afternoon. It updated 3 modules, rebooted, then updated 14 more modules.
During the flash I noted 2 unexpected updates for XM Satellite in the 14 module lot somewhere near the last few. Now, I have only driven around since updating for a few hours, but I have to say the reception "seems" much better now. I will know on the way to work tomorrow as I barely got reception on that route enough to listen to an entire song.
A word of caution for those going to update their own unit: the instructions state for push-button start vehicles to place it in the Run position without touching the brake to start the truck. Make sure you sit in the truck while it's updating - it takes 30 minutes or so - because the battery run-down protection kicks in before it finishes updating and turns off the power. Lucky I was in there and noticed when the evic went blank and immediately pushed the button twice to get it back into Run before the radio lost power. It could have hosed the head unit if I wasn't watching. If FCA doesn't amend their updating instructions to warn people about this, they're going to get a bunch of bricked units back for warranty.
Other than that, there isn't any noticeable change to any Apps or icons or anything that would indicate an update other than the version under System Information. I've heard that Siri works better (don't have an iPhone, so I can't say), VR is better (which would be a huge improvement) and the unit seems more responsive. Your mileage may vary I suppose.
Time will tell, I guess. Happy updating!!