Here are some ideas for how to restructure existing playlists and add new playlists:
Social:
Arena - 4v4 Strongholds, Oddball, Attrition, King of the Hill, Capture the Flag, One Flag
Big Team Battle
Last Spartan Standing
Team Slayer - 4v4 Team Slayer
Rumble Pit - 8 Player FFA Slayer, Shotty Snipers, Rocket Repulsors, Vampireball, Ninja Slayer, Fiesta
Cage Match - 1v1 Slayer. No weapon racks will be active. Equipment will be available around the map. Infinite ammo for weapons. BR variant, AR/Sidekick variant, Shotty/Sniper Variant, Sniper/BR Variant, Sniper variant, Skewer Variant, Shock Rifle Variant, Energy Sword variant, Rocket Launcher variant.
SWAT - 4v4 SWAT gamemodes
Action Sack - 4v4 Fiesta, Team Snipers, Snipers and Shottys, Ninja Slayer, Rocket Repulsors, Team Skewers.
Infection - 24 Player Infection on BTB Maps. Survivors get Sidekick and Bulldog. Infected have Energy Sword and No Shields.
Ranked:
Arena - 4v4 Oddball, Strongholds, Capture the Flag, King of the Hill
Attrition - 4v4 Attrition
Lone Wolves - 6 Player FFA Slayer
Team Slayer - 4v4 Team Slayer
Team Doubles - 2v2 Team Slayer
Monthly Rotating Playlist - 4v4 Team Snipers, 6 Player FFA Snipers, 1v1 Cage Match (BR Variant), SWAT, etc.
Custom Game Browser would then be able to fill in the gaps and allow people to find/host specific modes they want to play, such as Infection, Team Snipers, Grifball, etc.