That is generally the price you pay for being a streamer/celebrity, for better or worse. He'd experience it on other games, as practically A LOT of other prominent streamers do.
Not that I condone the behavior at all, because I don't - I find it utterly repulsive and disgusting. But I don't think you can be a streamer the size of Asmongold, and go into an MMO like XIV, and really think you're genuinely going to be left to play the game without disruption - Be it from toxic players, or other players/viewers that want to try and experience the game alongside him on the same server.