Why does Volkswagen wait for the DSG transmission oil to cool to 30 degrees before changing it?

I recently took my 2007 Volkswagen Golf to a main Volkswagen dealership for an oil and filter change on my car's DSG transmission. The garage rang an hour later to state it can only change the oil once it has cooled to 31 degrees and therefore the car will have to be in the garage till 2pm (this was now 9.15am). When I returned to the garage at the later time and asked to see the service manager, he said it was Volkswagen's policy to wait until the transmission has cooled to the recommended 30 degrees. I work as an engineer and have serviced automatic transmissions on earthmoving plant, whereby we always drop the oil when it's hot as this means the oil is thinner and most of it drains out pretty quickly. Have you come across this explanation?
Yes. Same with most modern car torque converter autos. The fluid has to be drained and replaced at precisely the right temperature and pressure. I know a DSG is not a torque converter auto, but I can understand the same rules being applied.
Answered by Honest John on

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