Truman Show Dropout
How do you know Trey Parker and Matt Stone wouldn't have wanted and been delighted to keep Chef in the show and continue to have paid Isaac even if he couldn't do any voices etc. for the show? I'm sure they could have found someone who could have come close enough to the Chef/Isaac voice.
They could have but Stone and Parker for whatever reason cut out other favorite characters from past seasons. Like Miss Choksondik, Mephisto and Jimbo.
I'm glad to learn the truth of why Isaac Hayes left South Park. Until now I thought it was Hayes choice to quit South Park because it dissed his religion. I had no idea he had a stroke and was further unable to perform the role. My respect for him has been restored and I'm disgusted by the cult's machinations and lying to make the cult look like it was being persecuted.