I would presume relic plans to set up events that reward players for playing during specific times. Something similar to the double XP weekends you see in BF4 and other shooters. In this case it looks like playing enough games during the event will award face plates.
But what good does XP serve? Maybe a doubled drop rate for war spoils, and the winning faction gets a set number of warspoils dependent on their effort (bronze = 1,silver = 3,gold = 5).