I did some searching and found that he retired in 2018, and that his wife passed away in 2019. She had dementia, so I wouldn't be surprised if he stepped down to help care for her. There's a resolution paying tribute to him at https://www.cookcountyil.gov/sites/default/files/agenda_35_2.pdf, starting on page 17. 

I can relate to what happened here. I've had the same kind of thing happen in news feeds, and over the years I've had a tendency to go right past the date and into the article. As someone who likes to pass along news articles myself, I now try to make sure that I check for the date first. 
As for Butler, I became aware of him having become a Cook County Commissioner many years ago, and my impression has been that he was happy with his new career. The article mentions that his recording career waned in the 1980s, and maybe his first choice would have been to continue recording if that hadn't been the case. But he charted on the Hot 100 from 1958 to 1977, and then on the R&B charts for another six years. That's a really good run, and I think it's also impressive that his career as a county commissioner ended up being even longer. 

Jerry did such a splendid job MC'ing several of the PBS specials.  He was so elegant.