MCC has a diverse community spanning nearly 20 years of players old and new, and the PC announcement will only broaden the scope of player expectations. The one-size-fits-all matchmaking style struggles to meet so many varying expectations. To keep such a wide variety of players engaged, sub-communities need the power to manage and organize their own tribes. An API could enable developers to streamline communications, game sessions, and leaderboards at the sub-community level. MS/343 no longer needs to focus so much on the playlist dance to keep players happy, and instead can help navigate players to their favorite community managed game night.
Microsoft at large is pushing to enable software developers, so I hope this trickles down to 343. Take the guess work out of the equation, and empower the community by empowering developers.