This still doesn't explain what "the backward group" has to do with generative AI, which didn't even exist in Mao's time. Hell, he says in the passage you linked:

The leaders must therefore be skilled in uniting the small number of active elements around the leadership and must rely on them to raise the level of the intermediate elements and to win over the backward elements.

(bold emphasis mine)

So he was specifically in favor of winning over the "backward elements", which contradicts with your implication that AI as agitprop is "unwanted by people" and somehow bad as propaganda because it would only "be effective agitprop [for] the backward group."

And…people don’t want it. The only people for whom it would be effective agitprop are the backward group.