The last known living US ace of the Great War died c. 1993:
James Pearson, an RAF Dolphin pilot. None of the US WW I aces reached 100 though some nonaces have done so.
Some of the WW II aces almost certainly will make their century. Right now my money's on Robert L. Scott (92) and Joe Foss (84), still going strong based on disgustingly healthy lifestyles. Somebody once asked what's the leading cause of death among aces, and in my experience, it's coronaries, cancer, and booze in approximately that order. Flak and fighters are waaaay down the list! In fact, operational accidents might outnumber combat losses.