rangerjean,
No, they are not the same thing. WD refers to the bars distributing the weight off the rear axle and sending some of it back to the trailer and most to the front axle of the truck.
Sway control is controlling the horizontal movement of the trailer back and forth. To do that there needs to be some way of damping or preventing that movement. Since the WD bars are free to swing back and forth as much as they want, they in themselves do not prevent sway from occuring. They may help with the steering however as they replace the weight lost from the front axle of the truck when the tongue weight is place on the hitch. They are not considered a sway control device however.
Many modern hitches now incorporate sway contol with their WD bars however. Hitches like the Reese "Straight Line" or Dual Cam, the Equal-i-zer, the Blue Ox :Sway Pro: and others are very popular and work quite well.
So no, the WD bars are not sway control devices unless the hitch manufacturer makes them a part of the sway control capabilities of the hitch.
I would encourage you to use the WD bars when you tow the travel trailer even though you have stout truck. You will find that they give you a better ride, even out the bumps, and help you steer your truck the way it was designed to steer.
Barney