It is pretty baffling that they haven't put this playlist in yet. I mean, all of last week they had both Regicide AND Team Regicide. Really? Just one would suffice, and Team Regicide is slightly better than normal Regicide. Nix one of those playlists and include the FFA.
My guess is 343i is going to wait till they push out their title update before releasing this playlist. Basically once Competitive Skill Ranks are out is when this playlist will be released. We'll see though.