SA, I almost agree. Your examples are borderline, they don’t require a conspiracy that expands without limit, but they are well beyond the typical propaganda by spin and omission. The global warming denial that has gradually petered out of the corporate media over the last decade or so did require unlimited conspiracy.
I think that reliable, verifiable, correctable mass news media would provide a major remedy to the proliferation of conspiracy theory on social media. People aren’t sheeple; they know they are being misled, but structural propaganda is complicated to pull apart and correct, so conspiracy theory arises in reaction.