Being the voice behind Saturday Night Live for many years has solidified Don Pardo's place in history. He has made his mark as a radio and tv announcer for many popular programs and people recognize his voice. Pardo will be difficult to replace as his voice was unique and had a charisma that is difficult to replicate.
The work Don Pardo did on Saturday Night Live was incredible and the stuff of legens. He introduced the world to countless stars and became somewhat a star himself in the process. There's no reason that he won't go down in history as someone who gave something back to society through his work.
The heyday of SNL was long ago and many people don't even pay attention to the show. While it's sad to lose entertainers it would seem that Pardo had a long and beneficial life and there's no reason to be sad when someone lives life to the fullest and dies of old age. I don't think he'll be a historic figure.
While I greatly admire the work he has done I don't think he will become a historic figure. There are a lot of people who have done a lot more who aren't remembered, I don't know what would make him any different. He was a great announcer and has a great history at NBC, but noting truly historical.