DICE is awfully busy these days.
During a new Polygon interview , DICE general manager Patrick Bach confirmed that the team actually has three games in the works right now:
"We have three projects in the works right now. …did I say that?"
Chance are, it's a new Battlefield installment, which means EA is bringing the franchise back to DICE after Visceral Games delivered Battlefield: Hardline in March. We do know the next Battlefield is slated to arrive at the end of 2016, so maybe this is what Bach is referring to.
If it isn't, then it's a mystery.