Did the Fremen ever reinstate mortal combat to become Naib after Muad'Dib became the Mahdi?

Question

To become the Naib of a sietch a Fremen they must call out the current Naib via the tahaddi challenge and kill them in mortal combat.

Muad'Dib refused to kill Stilgar, Naib of his steich, when asked by the Fremen to become their leader.

Paul said that it was a waste of their best leaders and instead named himself as the Mahdi and Naib of all Naibs.

Was the tahaddi challenge removed as a requirement to be Naib for everyone? Or was Paul a singular exception to the rule? If it was removed or outlawed, was it ever reinstated?

Answer 1

We don't know.

It's hard to prove a negative, but the Dune wikia agrees with me. I know that counts for little without sources, but we simply don't see any Naib ascensions in the books after Paul becomes Naib, Mahdi and finally Emperor.

If I'm allowed to speculate, I assume that Paul's words about not wasting their best leaders weighed heavy with the Fremen after they bestowed him his role as Mahdi. In a practical sense, I also think the abolition of this practice would be natural to enable them to carry out their jihad.