This is based on a recent study by someone at the University of Southern California. I haven't looked into the study, so I can't really say how credible it is. Since the Russian "troll factory" is a hot topic these days, parts of the media ran with it, possibly blowing it out of proportion.

I'm with you on being annoyed at the vocabulary used to describe these propaganda campaigns. "Fake news" was originally solely used when talking about the web sites masquerading as news organisations to make a quick buck on advertisement. Then parts of the media started using the term also when reporting on the Russian propaganda campaigns, some even muddling the two together. Then those who prefer the version of reality presented by the propaganda machine started using the term to describe real news. And now the term is basically meaningless.

But the bots is a real issue. An army of bots is an effective way to steer the conversation on social media, especially on Twitter, which has proven especially vulnerable to such campaigns.

So why would Russian shills waste their time on something as insignificant as the Star Wars fandom? My guess is there simply wasn't much important going on during that time, but people on the payroll needed something to tweet about. A big controversial film release is a good chance to cause some minor havoc during political downtime.