Back in the 80's I ruined an engine in a car my folks had by forgetting to shut it off. Was in a driveway, 120 F, Arizona. Overheated and seized up.
The references to prolonged idling I can find talk about the dangers of not reaching operating temp and going over temp. Both have their dangers. The same holds for oil pressure, mainly, the damage done by under pressure.
I don't know if an idling Tundra has either of these problems but it wouldn't be hard to monitor. Obvious wear and tear on pulleys, belts, bearings, fluid life, etc have to be factored in.