"The settlement ends a legal dispute that some of Parksâ own relatives had criticized, saying she wouldnât have minded the use of her name in the song âRosa Parksâ had she not been mentally impaired. "
...
"After that lawsuit was filed, some of Parksâ relatives began questioning her well-being and the actions of her caretaker and the lawyers who filed the suit, and alleged she is probably unaware of the lawsuits."
So perhaps while she did technically live long enough to sue OutKast, she was suffering from dementia at the time and it's possible that she was unaware of the actions taken in her name.
It really shouldn't be TOO surprising, but she was a bit of a fighter. Particularly when it came to her civil rights in most matters, but also in reguard to her own name and likeness.