Exactly. What you've described isn't evil. What would be evil is creating a society for those people where all truth is suppressed, all irrationality is praised

Exactly. What you've described isn't evil. What would be evil is creating a society for those people where all truth is suppressed, all irrationality is praised, good deeds are punished and amoral behavior is rewarded. Basically, making that society as backwards as possible. And if in a few generations people there will embrace that order, because they don't know any better, and start descending into animalism, that would be an example of evil. In other words, evil operates at the soul level, so if you reject the idea of soul, you won't be able to come up with evil or good plans: all acts will be superficial.