As someone once pointed out, these days game marketing is not needed at all, what with all the leaks for upcoming games that market themselves. This is the case with Halo Infinite, another in a long line of games with leaked content.
Halo Infinite is an upcoming first-person shooter game developed by 343 Industries and published by Xbox Game Studios for Windows, Xbox One, and Xbox Series X and Series S. The sixth main entry of the Halo series, and the sixteenth Halo game overall, it continues the story of the Master Chief, following Halo 5: Guardians. Unlike previous installments in the series, the multiplayer portion of the game will be free-to-play.
Several subreddits have had posts surface regarding Halo Infinite leaks. The leaks in question are twelve hundred lines of transcribed in-game conversations and events, between Master Chief and his AI companion.
Storywise, the game seems to start out with a simple Search and Destroy mission, that evolves into retrieving UNSC assets and personnel. From there, Master Chief goes on to discover the mysteries of Mjolnir, and encounters foes such as a Sangheili Blademaster, with the Banished being one of the enemy factions, and the Harbinger being the mastermind behind everything.
As far as multiplayer is concerned, from certain Master Chief's quotes, we can expect multiple game modes. What can be extrapolated is that those game modes include restrictions such as limited lives, perhaps even a last man standing mode. A mode where altitude plays a major role, perhaps some aerial combat, and other, simpler modes, such as capturing and holding points of interest.
Of course, none of this is yet commented upon by the developers, but it seems too big of a leak for it to be a red herring, or for all of this to be changed in a short period of time.
Still, as always, take leaks with a grain of salt, and don't go too far into spoiler territory.