It’s a load of rubbish. It’s not the 1960s now. Modern engines warm up better and more efficiently when moving not sat idling. Cooling down period holds the same myth. The engine management computer takes care of that after you’ve turned the key to off so the driver doesn’t have to sit wasting fuel and putting unnecessary emissions into the atmosphere.
I’ve not known a turbo to fail on a truck either in warranty or out of warranty when operated like this.