You might already have figured this out, but 343 Industries, the Microsoft-owned studio behind Halo: CE Anniversary and Halo 4, is continuing to develop for the franchise with Halo 5: Guardians. With two blockbuster entries in the series under its belt, it's safe to assume that the developers at 343 know what they're doing.
It also helps to have shaped the previous entry in the franchise, which put much more emphasis on building Master Chief as a relatable character. This came to a head in the ending of Halo 4--and Halo 5: Guardians will be about Master Chief getting through his identity crisis. "He's questioning everything: His past, his purpose, what's he fighting for, why he's fighting," says 343 studio head Bonnie Ross. "This is about [Master Chief's] journey. It's about his past, and about his future".