Sketch posted recently on Waypoint stating that detailed on-line statistic tracking for Halo: Reach will end on March 1st. What he referred to as "your high-level stats summary" will still be visible while the carnage report and all in-game functions will remain unchanged, and detailed stats will still be visible in-game via the service record. Reasons cited include "aging hardware issues and evolving customer privacy and security requirements across Microsoft" and the fact that the game "was built in a different era using old hardware, systems, and code that just doesn’t scale to meet the requirements of the future". Sketch went on to point out that Reach still has a healthy population but very few players check their stats on Waypoint.

source:
https://www.halowaypoint.com/en-us/forums/cdecc00475c645b9a4d0a156fb542d59/topics/halo-reach-detailed-web-stats-retirement---3-1-18/b5e734e7-2b16-448b-b5ee-8b2f6714bc65/posts