You won't have to wait until E3 to see what's next in the Battlefield series. Some folks found an easter egg in one of the maps, which had a painting and a dripping pipe. As detailed by Polygon, a certain order of breaking signs and flipping switches lead to a door opening in the Fort Vaux map.
Inside the room was a painting of a horse and the sound of a dripping pipe. The pipe was morse code for the url, ea.com/neverbethesame. Going there just has a an image of May 23, 2018 with #battlefield underneath.
You can probably deduce that that's the day we'll get information on the next Battlefield game, which is rumored to take place in World War II. June 9th's EA day so we're going to get info a few weeks before that event. Battlefield 1943 was the last one in the series to take place during World War II and with the success of Battlefield 1, it's not unthinkable to see EA heading into that territory for the next game.