Have you seen their pay and W-2's? They upgrade in the right seat of a small 737 if pay is how you define upgrade.

Now if its 4 stripes with less pay that's the goal, that can be had way quicker at any of the myriad of LCC's endless growth that DL is funding with endless "capacity dicipline" to keep their order books alive and keep them in growth mode to keep their costs low.