It doesn't matter if a console developer is trying to hone in on the competitive scene or capture average gamers for multiplayer, they all tend to face the same issue - a sudden drop in population. Usually games like Call of Duty or Battlefield only keep a large online population for a few months before gamers move on to a new title, often never return.
Once that population is gone, the chance to create a competitive community around it are also sunk. Console games simply lack the staying power that PC-based titles like League of Legends or CS:GO have to keep a constant population going. Adding in small amounts of new content to keep attracting new players and bringing back old ones helps keeps these titles fresh without changing too much.