Even well before launch, it's been leaked that Call of Duty: Modern Warfare will be incorporating classic Call of Duty multiplayer maps at some point. Infinity Ward has yet to announce any such plans, though fans have now spotted a couple of classic Call of Duty: Modern Warfare 2 maps that are visible from other maps that already exist in the game.
YouTuber Blame Truth Archives has posted a video showing the Modern Warfare 2 maps that he found in Call of Duty: Modern Warfare. Those that want to watch the video can click here, but do note that it contains some strong language, as Blame Truth Archives is annoyed that these maps are in the game already, but aren't playable. The maps in question are Modern Warfare 2's Invasion and Scrapyard maps.
Invasion is adjacent to Euphrates Bridge and can be found if players explore the map with a free camera. Scrapyard, meanwhile, can be found in the Spec Ops co-op mode. It stands to reason that since Infinity Ward already bothered incorporating these maps into Call of Duty: Modern Warfare in some capacity that they will eventually be added to the game as proper multiplayer maps, though that remains unconfirmed at the time of this writing.
In the meantime, some may be wondering why there are multiple instances of Call of Duty: Modern Warfare maps being visible from other maps and areas in the game. Besides the aforementioned examples, players can see the Tavorsk District map from Krovnik Farmland when playing Ground War. There has been some speculation that this is because Infinity Ward is going to incorporate these maps together to make up the Call of Duty: Modern Warfare battle royale map.
The Call of Duty: Modern Warfare battle royale map leaked just recently thanks to datamining efforts. It will reportedly feature a staggering 200 players when it finally launches, though a release date is unknown. Previous leaks have pegged the Call of Duty: Modern Warfare battle royale release date to be some time in 2020, though nothing official has been announced.
In the meantime, fans will have to keep scouring the Call of Duty: Modern Warfare multiplayer maps for clues as to what's coming next.
Call of Duty: Modern Warfare is out now for PC, PS4, and Xbox One.