I doubt this originated from Ali. According to reports he is only able to gesture and grunt to make his needs known. His family might have written it and asked him if it was OK, but I seriously doubt he had much to do with it.
From October 17, 2014, UK’s Dailymail.com: “Painfully frail, his face an expressionless mask, he usually communicates his needs via a series of grunts and gestures comprehensible only to his fourth wife Lonnie and her younger sister Marilyn, who serve as his carers.”
Agreed, I met him in his home about 5 years ago and he mostly grunted and used gestures then. Parkinson’s had really taken over his body and he could barely walk then. This came from a spokesperson or a group associated with him. Also, I did not see any evidence in his home that he or anyone else in his family were Muslim.