I went to one for a candidate for the House district I lived in a few election cycles ago, It was mostly stump speeches and other “rah rah we’re gonna win!” style pontificating. But one thing I did not expect and I actually found interesting was the house candidate spent a lot of time introducing other local politicians that were in down ballot races in the district. City council seats, education board seats etc. That turned out to be really useful, because it meant I got to meet/ hear from candidates who I either had no idea existed or who were just a name of a flyer before then. I suppose that experience may not transfer to a national candidate rally though.
Even if you accept the claim that they were duped at face value, what does that say about them? These folk’s whole pretense is that they can “see through the media’s lies” and that they are able to tell what is really going on. But they were not smart enough to recognize that they were part of a propaganda campaign? They want you to believe they have a sophisticated ability to recognize media manipulation but also now want you to believe that they were hapless stooges that were tricked into participating in a media manipulation campaign.