Additionally, two new map variants created in Forge World--one by Bungie's Lars Bakken and another by a member of the Halo community--have been added to official playlists.

The Bungie created map variant is "Crossfire", which is seen above and will appear in the following playlists: Rumble Pit, Team Slayer, Team SWAT, and Team Objective.

Atom, the map created by JoeSki73, will be available in Team Slayer, Team Snipers, Team Objective, Multi Team, and Big Team Battle. A fly-by video of the map can be found below along with the change notes for the playlist updates.

The playlist changes are as follows:

Playlists
• New Playlist: Team Snipers
• New Playlist: Living Dead
• Rumble Pit
  • Lineup rebalanced to offer more kill, less frill.
  • Removed Infection, Safe Havens, Race, Rally, Headhunter Pro
  • Removed "Classic" gametypes
• Team Slayer
  • Removed all Snipers gametypes
• Team SWAT
  • Added SWAT Magnums gametype
• Team Objective
  • Removed 1 Flag Classic
  • Removed Headhunter Pro
  • Removed the following gametypes from Hemorrhage due to the size of the map with only 8 players:
    • Multiflag Classic
    • 1 Flag CTF
    • 1 Flag Pro
    • 1 Bomb Assault
  • Removed Oddball and Hot Potato from Boardwalk
• Multi Team
  • Removed SWAT
  • Removed Classic gametypes
  • Removed The Cage
  • Changed weighting for Rocket Race so it does not have a 100% chance to appear in Slot 3
• Big Team Battle
  • Removed Multiflag from Boneyard and Spire
• Invasion
  • This playlist now offers 3 voting options
• Firefight
  • Updated Firefight playlist gametypes to be a full set instead of 1 round. Adjusted skull progression.
  • Removed Friendly Fire
• Score Attack
  • Removed Crash Site
  • Added Mythic Score Attack
  • You can no longer pickup other weapons in Sniper Attack

Maps
• Zealot/Arena Zealot
  • Arena Zealot is now used for all Slayer gametypes
  • Players can no longer stand on the edge of the generators in space and crouch to shoot below the shield
• Asylum
  • Softkill zones added to the tops of the Sniper buildings
• Boneyard
  • Modified respawn zones for Slayer gametypes
• Hemorrhage
  • Modified respawn zones for both bases
  • Respawn timers for all Warthogs on Hemorrhage should now be 120 seconds

Gametypes
• CTF
  • All CTF gametypes should now have a player respawn of 10 seconds
  • All Classic CTF gametypes now feature Flag At Home To Score and Touch Return
  • Flag At Home To Score disabled for all non-Classic CTF gametypes
  • Modified Flag Return and Flag Reset times:
    • 1 Flag on Small maps use 10 second return and 30 second reset
    • All other CTF gametypes use 30 second return and 45 second reset
• Assault
  • Assault gametypes now have a player respawn time of 10 or 15 seconds depending on the map

Additional details and the full notes to the Firefight changes can be found at Bungie.