I haven't been able to confirm the number of players that can hook up together online, but for sure at least two players can play together in what seems to be a co-op survival mode. Keep reading to see a detailed list of what's included in the update.
// WHAT'S NEW IN CO-OP //
NEW MODE: CO-OP EXTERMINATION
Automatically match or team up with friends to exterminate renegade battle drones before the reactor explodes.
NEW WAYS TO GET GEAR
Collect weapons, armor, items and credits from demolished battle drones in CO-OP Mode and recycle extra gear for credits.
ENHANCED GLOBAL MATCHMAKING
Quickly connect with other players automatically in Global matches based your rank and skill rating
10 multiplayer environments including the all new Annex and Junction maps
// 100% COMPATIBLE WITH ELIMINATE PRO! //