Although there's no official statement from Treyarch or Activision, it's clear Black Ops Cold War implements SBMM in Multiplayer. The matchmaking pairs you up with similarly skilled players in nearly every lobby, which is the main proponent of SBMM.

Will Cold War have skill based matchmaking?

Black Ops Cold War matches players with a similar level of skill in order to create a competitive game. ... With players wanting a more casual experience, here's how to TURN OFF skill-based match making in Black Ops Cold War.

Will there be SBMM in Cold War?

Not only is SBMM returning, but the leak also states: “It'll be the same as it is in Cold War.” The Cold War system has often been criticized for matching high-ranking and winning players in lobbies that descend into a CDL scrimmage, which isn't what everyone wants.