Focus on Gameplay: Black Ops Cold War focuses on online multiplayer and cooperative modes, or the campaign story. There's no in-game phone system for transferring calls.
Burger Town Easter Egg:
This easter egg in "Red Light, Green Afghanistan Phone Number List ight" lets you interact with the mascot of the fictional fast-food chain, Bubby the Burger Town Boy.
By pressing a button, you can hear funny voice lines related to the Cold War.
At one point, Bubby might even "give" you a free grenade launcher!
No Phone Calls Involved:
While the easter egg features a fast-food restaurant, there are no phone calls or transferring calls involved. It's purely a humorous interaction within the campaign mission.
Overall:
"Cold transferring a call" is a real-world phone communication practice that doesn't apply to Black Ops Cold War's gameplay, even with the Burger Town easter egg.