It’s also over explaining why he isn’t in Star Wars. (Or the end of ROTS.) It’s logical to presume he simply passed away in the intervening years.
How about he died from an infection in his leg due to bad medical treatment and a general apathy from losing his wife? He stopped caring for himself. That way he technically died from a broken heart, but its not Lucas level stupid.
As for the Prequels, they happend but Disney should focus on the good aspects of Star Wars going forward. No Hayden in The Last Jedi, though if he was in it and say the movie only did 1.2 billion they could blame it on him and you would never see a major PT reference in a Star Wars movie again.