COD: WW2 will need a day one patch in order to play the campaign mode according to reports. The day one patch is needed because Activision put a limitation to prevent the leaking of campaign content. This means that the servers will most likely suffer from overloads due to everyone downloading this patch that is going to be 9GB which will take quite some time to download and install.
Some reports claim that PS4 players have already received the 9GB patch and can already snoop around in the campaign mode.
You can read more about this in this article By Gary Jones http://www.express.co.uk/entertainme...One-shock-news