With roaming I mean an AI that is practiciing to imitate 1:1 human interaction through chat. I mean the results that already exist are already almost indistinguishable to real people.

Why do i come to that conclusion? I am still an active user in almost dead forums, and sometimes some random people register there and actually start a bunch of threads, but they don't make any typos at all, they use their Full names instead of nicknames, and generally they write as if theres no "soul" inside them. Why would you do that? well it comes down to keeping people busy. Whats the difference playing vs Humans or an AI when you can't distinguish them anymore? well you can create all kinds of Informationbubbles, youtubers with thousands of AI subscribers and viewers, making indistinguishable comments. AI players filling up servers in online games.
AI filling up forums to keep people occupied and not think about themselfes. AI trolls to intentionally spread missinformation.