https://wccftech.com/call-of-duty-modern-warfare-does-away-with-prestige-system-using-enlisted-and-officer-ranks-instead/

Call of Duty has provided multiplayer progression through Prestige Systems for a long time. However, Infinity Ward is doing things differently with Modern Warfare, as revealed with a lengthy blog post.

There will be Enlisted Ranks and Officer Ranks. Your Enlisted Rank will never be reset; the game's developers have instead decided to add the Seasonal Officer Ranks, which will be tied to each season of content coming post-launch to Modern Warfare.