The firm's corporate vice president Phil Spencer said that the game "lost [its] way" without the character, who was missing from Halo 3: ODST and Halo: Reach.
"The key question for me in managing the studio and the creatives is, 'What is Halo?' making sure Halo lives up to what I think gamers fell in love with [playing Halo: Combat Evolved]," Spencer told Official Xbox Magazine.
"What does that mean? Playing Master Chief. We kind of lost our way a little bit, I'll say.
"And that's why I wanted to make sure that at the unveiling of Halo 4, you knew you were playing Master Chief, that John was back. Because Master Chief is the John Wayne character of that universe, and that's who you want to play."
Spencer added that Halo 4 will retain the familiar mix of linear campaign stages with open battlefields.
"Halo has this interesting mix of open world, more varied gameplay," he said. "Some other of those franchises that I love have very set pieces which really kind of draw certain dramatic elements out of it."
He added: "Halo has the vehicles, the weapon types, the deep fiction - the fiction around Halo is incredibly deep."
Series creator Bungie recently bid farewell to the Halo franchise in an open letter to fans.
343 Industries will re-release the original Halo: Combat Evolved later this year, while Halo 4 will start a new Xbox 360 trilogy in 2012.