I've got a 2016 Scat Pack Challenger with just less than 7,000 miles, & the rear diff is making noise. SOMETHING is going on inside. My biggest challenge now is finding a dealer with a good drivetrain tech to take it to.

The video says the lack of oil is from an axle not being installed properly. But the gear looks mighty dry.

The owner of that car must never do any kind of periodic checking. Like.... that's pretty dry. I could see the oil being LOW with an improperly installed half shaft.... but, to be completely empty??
I've had leaky diffs on a lot of my junk but none of them ever ran dry and we're talking old school diffs where the cover is the oil seal and is below the level of oil.

This thing would've been SPEWING oil at a noticeable rate. Or, more likely.... the shop that did the axle work.... if they did the axle improperly.... did they maybe drain the diff and forget to refill it?

You can clearly see the oil under the car , on the exhaust and on the axle - the seal probably was not replaced when the axle was replaced - a rotating axle leaking around the seal will pull the oil out of the rear end in no time - looks like carnage from a bad repair job!