My gut feeling would be that it doesn't affect it, but I have no data to back that up. It would seem silly to me to increase payload in the 2019, but make the tailgate such that it supports less weight. But stranger things have happened. That information has to be out there somewhere.

 

I just unloaded a 2,000 pound hale bale off the back of mine by resting one end on the ground and the other end on the tailgate, I was nervous but no issues at all.