The Prequels are about Anakain’s fall, the Originals Anakin’s dark deeds and eventually redeemption. I think the Sequels are about Anakin’s legacy.
Although I am against having Anakin return in any form, this is an interesting point.
In fact more broadly the Sequels are concerned with legacy and legends, while the prequels were concerned with visions and prophecy. Both look to the originals for their power.