I mean, that's the point of Dune? The 'prophesies' aren't real, they're seeded by the Bene Gesserit, the same group that spent millennia breeding the 'savior'. And, he's not meant to really be a savior, but their catspaw.

But also, he's definitely not actually a savior, on account of all the death he brings. It's complicated, but overall a deconstruction of white savior narratives and similar stories.