https://wccftech.com/modern-warfare-2-and-treyarchs-next-call-of-duty-game-featured-in-massive-leak/

Call of Duty: Modern Warfare 2 and Treyarch's untitled Call of Duty game are both featured in a massive leak that hit the Internet a few hours ago. The leak originated from the Warzone Mobile Alpha, which contains files and even images pertaining to both games.

Dataminers like RealityUK did the rest, sharing a wealth of information with fans. Let's start with the (incomplete) weapons, perks, and map lists for Modern Warfare 2. Do note that most of them are still written down in codenames, and multiple map codenames could refer to a single map, so this isn't necessarily an indication of how many maps will be in the final game.