It does not go back to the First World War, it always remains at World War II, but an important step back was made by Sledgehammer, developer of Call of Duty: WW2, which has finally reactivated i dedicated online game servers of the title as it was at the exit of the game.
Initially, the shooter could rely on a dedicated server infrastructure, but after some problems the software house had decided to use P2P, functional but certainly not comparable to an online multiplayer that can rely on specific game-specific servers. One of the problems with P2P, for example, is that if the host disconnects for any reason, the game hangs for a few seconds while the game "transfers" the host role to another player.
The problems of dedicated servers have been resolved and then Call of Duty: WW2 can again count on a solid multiplayer game, albeit at the moment there seems to be still some small problem found by a low number of players. Probably servers will still have to stabilize completely, which we hope will not take longer than the due.