The next Battlefield game will be set in World War 1, according to leaked in-store promos.
Battlefield 5 will apparently be called "Battlefield 1", and as you guessed it'll take place in what could be an alternate WW1 setting. The leaked promotional artwork has also been shown off on the Xbox One's marketplace, pretty much confirming the original artwork. Besides the obvious weaponry, it looks like there's a huge zeppelin looming in the upper right hand corner.
The studio has since released a brief teaser showing in-engine footage, and DICE is set to reveal the game today during a live stream at 4PM EST. We'll be sure to keep you updated on all the latest Battlefield news, and the devs will reveal tons of extra tidbits about the new Battlefield at the show.