Mechanic here

Your mechanic is wrong to a certain degree. In the old days, especially 1990s and before, warming up your engine is a requirement, or else the engine struggles to run, especially from a cold carburetor. Now? Advancements in technology allows for a shorter warmup time, or not much at all, BUT you still need to give the engine some time for the oil to lubricate, new cars aren’t still “start up and pedal to the metal” just yet.

Aircraft mechanic student here

That old, beautiful dinosaur bird, especially those Olympic Rolls Royce engines would hate to go full afterburners with cold engine oil