I live in a desert climate where it not only hits 46C, but does so for literally months on end. This article is utterly BS. Trees do fine, even an huge number of imported species from significantly cooler climates.
They survive, they're not 'doing fine', if they did you wouldn't live in a desert climate for long. High temperatures have a very visible effect on vegetation, so much so that you can trivially pick these out on satellite imagery.