Are Duster rear bumper corner brackets important?

Along with all of the other points for retaining them, my guess is that the factory put them on to add more rigidity to the bumper when the bumper jack was used to change a tire. I bought a rear bumper core for my 70 Duster at Mopars at The Rock the other day and was glad to see the end brackets there since I don't remember seeing them on or in my Duster anywhere.