There were already talk that the next Battlefield game could be set in World War 1 but EA and DICE never really confirmed that rumor but who needs them when we have Microsoft right?
Whether it was intentional or a mistake, the fact was that Microsoft posted on image of the game on their Xbox One Xbox Store. A NeoGAF user spotted it and posted it on the forum. There is no mistaking it for another game since the image came with the line “Road to Battlefield”
The image showed what looking like a man holding a WW1 grenade and German Luger pistol which sort of confirm that the game will be set in WW1. An employee from EA later tweeted “Wow M$ Just wow” but later took down the tweet.
EA officially announce the game soon after confirming the rumor. They also reveal that the game will be release on the 21st of October.