just wondering
Yes! 4-player splitscreen and online. Enjoy your day.
Speaking of Co-OP, we don’t know if P2,3,4 will be Green Spartans that look very suspiciously similar to Spartan 117, or anything like that, but there will be 4-player coop.
343i announced that all future Halo titles will feature split-screen. For multiplayer I am assuming that means 4 players, but the campaign usually restricts the local player count to 2.