Nope, that's her title and in my honest opinion, she earned it. I cannot say there is someone today other than perhaps Ms Patti that can compete for it. And I don't think that Ms Patti wants it because she's a queen in her own right.
Who really knows what will happen in 100 years. Elvis has been gone for many years and he is still known as the King. Sometimes the title just sticks with you. New titles are given to those who earn them.
It's an unofficial title, for life. When Aretha is gone someone else will undoubtedly be given the same Unofficial Title. James Brown was the Godfather of soul. I don't think anyone will ever take that title away.