Stuff fails. A moving pole changes the direction of force drastically. The bars get smacked into steering stops 100 times a ride, someties very violently. Not having a bend in them does decrease strength.
If its a real pain in the ass, go get a piece of bar stock from the steel yard for 15 bucks for 20 ft, and make your own length bars, and a bunch of spares. You can get thicker wall, or solid stock if your worried about strength.
Good to see they are taking care of ya, I persoanlly would have liked my new bars first so I could ride, but anything is better than nothing.