It's also worth noting that Infinity Ward has carefully played with some of these maps without outright remastering them.

Source: https://comicbook.com/gaming/news/call-of-duty-modern-warfare-2-mw2-new-classic-map-future-update/

Just weeks after the mode was initially released, Infinity Ward removed Gun Game from Call of Duty: Modern Warfare 2, a choice that left many angry with the developer.

Source: https://gamerant.com/call-of-duty-modern-warfare-2-rebalancing-op-weapons-season-2-reloaded/

There, Infinity Ward explained that the fourth unrevealed weapon would be a "high-caliber pistol modified for full-auto," which certainly fits the bill for an automatic Desert Eagle firearm.

Source: https://gamerant.com/call-of-duty-modern-warfare-2-fourth-season-3-weapon-leak/

This means that, in effect, the US military will eventually adopt the SPEAR weapons platform, making it all the stranger that Infinity Ward chose not to implement its most interesting offering.

Source: https://gamerant.com/modern-warfare-2-battle-rifle-cronen-squall/