Much to the dismay of some fans, Halo 5: Guardians will not come with split-screen cooperative play when it comes out. It’s a major change for the Microsoft-developed game as every other Halo console title came out with the feature. But according to Microsoft General Manager of Games Publishing Shannon Loftis, this doesn’t mean it won’t possibly get the feature in the future.
Loftis said in a meeting at E3, "The priority feature for the release of Halo 5 was 60fps, so that's what the team has been focused on delivering. But, you know, never say never. The glorious thing about Halo and about Xbox is that we can deliver continuous improvements to any experience. But, no announcements being made here." Again, she isn’t confirming that it will get split-screen co-op but she is talking of the possibility after the game is launched.
Source: Engadget