"It's a sickening revisionism"

No its not. What WAS sickening were the individuals that attacked him in the first place. The people who called him a communist weren't liars, they were just ignorant.

Neither Pete or his "groupies" feel shame about his politics, and THAT is what gets his detractors angry. They seemed to get some sick joy out of watching people squirm and it kills them that people like Pete were able to lead successful and inspiring lives. Pete is still around, and many of the sick individuals who attacked them are long gone. Pete showed them all, and that really irritates some people.

The gracious things is that Pete realizes where he was wrong and apologies for his blind allegiance, but he never apologized for doing the right thing.   He forgave others, and he performed in concert with Burl Ives near the end of Burl's life.