They removed PLUNDER because players were getting to much XP from it and leveling thier guns to fast. In this new mode you get 90% less XP. The more you know.
Plunder is a respawn-enabled, squad vs squad mode where the team with the most Cash wins. Cash can be earned by eliminating players and picking up their valuables, scavenging for Supply Boxes and loose Cash, or completing Contracts and in-game events.