https://www.techradar.com/news/halo-tv-series-will-be-an-original-story-starring-master-chief

Showtime has confirmed that its upcoming Halo TV adaption will see Master Chief in the leading role and will explore an entirely original story. 

During Showtime's panel at the Television Critics Association press tour, president David Nevins and president of programming Gary Levine confirmed to GameSpot that Master Chief will feature in the upcoming series. Better yet, he will be the lead character.