I worry that young audiences now will have no idea who he or Lionel Hutz are. They were staple secondary characters before Phil Hartman died, and two of my all time favourites. I don't want to sound like one of those guys that says The Simpsons sucks now, but... well, The Simpsons sucks now. Seasons 1-8 were brilliant, funny and clever, so it'd be a shame if any fans now never get a chance to see them.
Right in the nostalgia. Troy McClure was and still is my favorite Simpsons character ever. Phil Hartman was tremendously funny on SNL as well and his standup routine was epic. He had a bit where he would impersonate John Wayne's voice perfectly but in European languages.