"Could not complete matchmaking." Error Message

Treyarch pushed out a playlist update that broke matchmaking for the game. Just posting so people are aware of the issue and don't start troubleshooting their Internet connection like the game suggests.

Edit: This affects Warzone, Zombies, BO6MP but not MWIII.

Edit 2: Issue should be fixed. If you are in the lobby (ie. you see your operator moving), back out and go back into the lobby, or restart your game.