I feel with the current slate of games coming this year that we know of, Diablo 2 is it. I think Diablo 2 is going to take at least half if not more of all of the NA player base for the game. I know there’s always those “WoW killer” games that come out and are always, usually wrongfully, assumed to kill a said game. I remember path of exile for example delayed their big league due to thinking Cyberpunk was going to take all their streamers away.
But I think Diablo 2, especially being on console and PC, is going to kill out the remaining players. ESPECIALLY with the big level cap content update being released in December.