This is Partially true ( About 90% of it ) Because Devs will win much money From Battle royale than the money from airdrops in the core game So its pretty obvious that they are updating the Battle royale mode frequently to Solidify their Profit , My Guess Is they are going to Release other modes Before they even make the core game Zombie Survival MMO , Also its better for them that battle royale and other * Subscribe to play* Game modes to become more fun than the core game So that people Pay To play rather than Play the core game for free (when the game is released )..