Halo 5's 4-Player Co-Op Allows for a Much More Sociable Story - GameSpot

Microsoft explains why it's focusing so heavily on four-player co-op with the upcoming game.
A new entry in the Halo franchise was announced at the Microsoft Press Conference at E3 2013 for the Xbox One.

Halo Infinite Co-Op Campaign Is Now Playable With A Glitch, But Beware - GameSpot

4-player splitscreen co-op runs perfectly on Series X. : r/halo

Halo 5: Guardians – Xbox One : Microsoft Corporation

Xbox Head's Excuses For No 'Halo 5' Splitscreen Are Nonsense

Halo Infinite's Canceled Local Co-Op Is A Huge Betrayal

Halo 5's 4-Player Co-Op Allows for a Much More Sociable Story - GameSpot

Halo 5: Guardians, Halo University Wiki

4-Player Co-op Glitch, Halo Alpha

Halo 5 Will Deliver Epic Scope and Scale and Drama - GameSpot

Halo Infinite's King Of The Hill Twist On Firefight Co-Op Arrives On December 5 - GameSpot