With Titanfall 2 releasing later this year, it appears that Respawn doesn't have quite enough on their plates. A new job listing has popped up for an unannounced, 3rd person adventure game that will use Unreal Engine 4.
There is no other information listed about the game and only techical requirements for the position were listed, but a 3rd person adventure game is obviously the opposite of what Titanfall has come to be. This game will obviously have a single player campaign, because what 3rd person adventure game doesn't, but we know nothing else about the game currently.
The game will obviously not release this year with Titanfall 2 coming this fall and also they are still hiring positions to be filled for production. At this point, it doesn't make much sense to even guess at what the project could be, but we'll let you know as soon as we here more.