Yes, Halo Infinite will have local four-player split-screen multiplayer." [Published in StealSeries.com - Their Source: 343 Industries Live Stream - Republished in CogConnected.com] - Fact or Fake? : r/halo
Steam Community :: Guide :: How To Play Local, Split-Screen Multiplayer (VS. and COOP)
Halo 5's 4-Player Co-Op Allows for a "Much More Sociable" Story - GameSpot
Co-Optimus - FAQ - Halo 4 Co-Op FAQ
Halo Infinite isn't getting split-screen co-op, but fans have figured out how to do it anyway | GamesRadar+