I disagree, evidence for a lot of these sorts of things only tends to come out when viewed in hindsight. We know this is technically possible, we also know there's a large incentive for various groups to do so. Furthermore the harm done from assuming this is happening even if it isn't happening is much less than if it is happening and we overlook it. Consider that Google is known to alter search results to suit what it wants to guide society towards (for a mundane and harmless example, boosting the number of female CEOs shown when image searching for CEO), Facebook has previously experimented with its systems to see if they can influence people's moods and Twitter is apparently 20% bots (with a ton of them impersonating Elon Musk in reply to all of his tweets). From that it isn't really much of a leap in logic that other companies and/or governments also employ tactics to manipulate public opinion through social media, where botting is a pretty easy method (my most direct experience with something similar has been fake SpaceX streams shortly after an actual launch with 40k "viewers" posting messages about how they just got their doubled cryptocurrency back from Elon).

Honestly this sort of thing doesn't even need fancy language models when all you need to do is manipulate votes and collect a large number of human made posts with keywords and what they were in reply to and pay for some cheap labor to filter out false positives. Then just spam them back at similar posts.

We have this weird thing about asking for evidence of every claim made, but the entire point of conspiracies is that there's a strong reason to believe something is happening but the evidence isn't clear.