We're aware that some users are experiencing longer than normal Matchmaking search times. We are actively working on a fix for this issue.
— Halo (@Halo) November 11, 2014
Related: Halo: The Master Chief Collection review
According to Halo Waypoint, 343 has released server updates that should expedite the search times. The developer continues to monitor the situation and apply further updates to both the game and its servers as necessary. 343 asks that fans keep them posted on their user experience, reporting any issues on the game’s support forum.