The sources being some “researcher” from The Federalist who in turn cites a reddit account is about as weak of evidence as you can get.
At the same time its blatantly obvious that this has been going on for over a decade. Both parties and every super-pac run volunteer brigading operations come election season. Maybe some subcontract it out. Maybe some of them have actual bot-nets. Either way astro-turfing social media is the new way to manufacture consent. Russia was just late to the game and embarrassingly obvious in its attempts.
Bots on reddit are absolutely a thing. Ever since reddit’s API went private it became exclusively a for-profit venture for manufacturing consent.
If anything the foreign bots have gone down recently but national bots have gotten out of control. Given our political climate I suspect kumbaya posts of being bots more than anyone being polarizing.