Skill-based matchmaking is a system that multiplayer games often use to place players with similar skill levels in games with each other to fairly balance teams and maximize the enjoyment that players gain from the game. Since this video is relatively new, it's a good example of an updated matchmaking experience. Skill-based matchmaking has made Infinity Ward and Activision make a lot of money due to player retention, and there doesn't seem to be any incentive for them to make a change. Former Senior System Designer at Activision, Josh Menke, confirmed to GDC the existence and implementation of SBMM in COD game titles, saying that the games had some skill-based pairing and have always done so.
If you're curious about what types of players you'll find in Warzone, you'll want to know how the skill-based matchmaking system works. Infinity Ward and Activision have denied that skill-based matchmaking is used in Warzone and Cold War. Technically, Warzone has what's called commitment-based matchmaking, whose skill is a determining factor. This is nothing new, as skill-based matchmaking feels exactly the same as it did in the Cold War and the Modern War.
Enter skill-based matchmaking, a system designed to work in the background and pit against similarly skilled players during the matchmaking process. Call of Duty developers don't usually want to reveal any details about skill-based matchmaking. Infinity Ward and Activision have made a lot of money with skill-based matchmaking due to player retention, so they don't seem willing to change it. Infinity Ward and Activision use skill-based matchmaking to retain as many players as possible.