I moderated that sub through election season and then stepped down in January. At the end of the day the death threats and constant insults aren't what drove me away, but the organizational chaos. No one could figure out how to lead that team, and leaning on practiced organizational structures was apparently too hard for a group of redditors.
Yes I would expect undercovers to be undercover to other mods. Like imgaine some random guy starts some subreddit adds a few friends as moderators right. Then it blows up, so some influence group decides they need to get in on it. They would certainly not be open about their strategy of gradual take over.
*E.g. Inherent Vice.
A more believable idea as it's based on fact is that Reddit is the playground of paid PR and marketing firms. Makes sense for a PR firm to have moderation powers too. (I suppose this might also be later Pychonesque or more like William Gibson?)
Are you, as a senior consultant, going to sell your team's time to a client at £750 an hour per person to astroturf on reddit? How do you plan on quantifying the benefits, vs the same budget going to the same team to influence traditional media and lobbying?
Heck I'd love to know any half-decent agencies that offer these services.