Given how easy it is to keep an average human from discerning reality (see the last decade of boomers/gen xers on Facebook as an example) and the massive potential to create slight variations with LLMs, I don't think a Stephenson-style misinformation propagation campaign is that far outside the bounds of possibility.

That's a lot of compute power to waste on it, but I would guess that that's what bot networks are going to be used for in the future (or already are, right now, if they're done mining bitcoin).