The DW is caused by worn steering and/or front axle components.
Father in Law's '98.5 2500, leveled
Friend had two '99 2500, one leveled, one lifted
My dad's '01 3500, stock
My '05 2500, stock
My dad's '14 3500, stock
Out of all of those, and all the miles, I know of only one death wobble episode happening, and it was to me on my dad's '01. It had at least 250k miles on it at the time, I was in a slow sweeping left turn at around 50mph, running empty. I crossed a diagonal expansion joint on the highway for a bridge and the front end started wobbling. I lightly pressed the brakes and slowed to at least under 40 and it stopped. I sped back up like nothing ever happened.
My dad said that is the first time the truck had ever done that (he was riding with me). That was a few years ago, and it hasn't done it since.
From my interweb cruising, it seems more likely to happen on a lifted/modified truck versus a stock one. With that said, it happened to me on a stock suspension, stock sized tire.
Death Wobble is the least of my worries.