https://www.gamespot.com/articles/microsoft-explains-why-halo-master-chief-collectio/1100-6454258/

Halo: The Master Chief Collection had a very rocky launch in November 2014. An ambitious game that packages together four Halo games and their multiplayer modes, the game struggled mightily out of the gate, with matchmaking times proving extremely lengthy and in some cases not working at all. Microsoft was quick to address the issues and the experience has improved dramatically. Still, Microsoft sees the issues as a "black eye" for the franchise. Last week, developer 343 announced yet another way it's making it up to fans and sticking with the game. The Master Chief Collection will receive significant updates and improvements over the next year or longer, including an Xbox One X update and a wider update that will "help bring it forward and modernize many of the game's systems to take advantage of Xbox platform advancements since its original launch." It's nice to see Microsoft's commitment to the game, but why did things go so badly at the start? Halo franchise director Frank O'Connor recently addressed that in a lengthy and thorough blog post on Halo Waypoint (via Polygon).

Starting off by saying he's no engineer and is making no excuses for what happened, O'Connor said, "in terms of chicken/egg scenarios, fixing the existing 'vanilla' Xbox One MCC was the Chicken that laid the Xbox One X enhanced version egg." O'Connor suggested that it wasn't always Microsoft's plan to revisit The Master Chief Collection, but there have been a "series of changes to the Xbox architecture," including the OS and back-end networking systems, that have "cracked open an opportunity we've wanted to seize for many, many months now."