I recently came across this article on Den of Geek about how the participation of streamers in the New World beta created unexpected gameplay issues. Specifically, the article talks about how streamers (1) warped server-wide PvP mechanics like territory control due to their follower base, and (2) created large congregations of players that ended up impacting server stability. There are other issues discussed as well, and I found it to be a fascinating set of problems to have. I'm curious to hear other people's thoughts on it, as I would think Ashes of Creation could have similar issues (though you could arguably debate whether the former is an issue at all). Article is linked below.
https://www.denofgeek.com/games/new-world-amazon-mmo-streamer-support-controversy-biggest-problems/