They did before for past Tests whenever they had tickets free although that's obviously rare for the Ashes so your chances will be slim but you never know, there's always some that cant go.
If I were you, I'd keep an eye on Ticketmaster exchange or Twickets, thats usually the more honest places where people look to sell their tickets for face value when they cant go and a third party is involved to ensure no one is cheated out of anything.