What would have happened after Dune?
This presents two more questions:
What would really have happened after Dune?
and
What was Dune all about?
The writer (me) is unsatisfied with the conclusions given by Brian Herbert and Kevin J. Anderson. The answer I would prefer concerns my second question.
I would say the whole Dune saga is a real gender war. Its (only) solution would involve all (human) women having the powers and abilities of the Bene Gesserit. The men, meanwhile, would remain normal but would develop superhuman abilities specific to each individual on consuming a relatively large amount of the Spice Melange.
Dune is/was about the setting up of male or technos-dominated power structures and knocking them down in turn. The last of these is the Spacing Guild. Undermining or destroying the Guild and the Bene Gesserit was the intention of the God-Emperor Leto 2 Atredes.
This allowed all the planets of the former Imperium to develop their own space programmes during the Scattering and after, independent of the Guild. Sandworms could be transported to inhospitable worlds in order to successfully or partially terraform them. This also prevented habitable worlds from being destroyed by the introduction of Sandworms.
The Spacing Guild and Bene Gesserit existed during the Imperium to limit technological development in order to control the populace by maintaining their poverty.
