I don't think it will die any time soon. People were talking about how MMOs would die soon back in the early 2000s, but still in mid 2018 many of them are going pretty strong. Right now I think that Battle Royale is in a bit of a bubble because it is the current trend/fad, but many thousands of people seriously enjoy these games. As a result, I think that the genre will die down quite a bit, but will still maintain a strong community of players for years to come.