06 BPY 2.0T FWD transmission.

Hey guys,
What is your opinion on a transmission fluid change?
Car is a 6MT 138k with unknown last time transmission fluid change.
Audi stealership told me not to change it. “Because of the high mileage just leave it as it is coz it will cause more harm then good” - hmmm never heard of that before, but even though I am able to turn wrenches, I’m not the guy that knows everything…

Should I just change it or not?
Any recommendations? Any feedback on Motul transmission oil? I use their oil for absolutely everything (2 stroke oil, dirt bike engine oil, this audi engine oil) but never looked into their transmission fluids.

Thanks guys.

Paulo

06 A3 6MT - APR stage 2+, APR turbo back, IE HPFP upgrade, Borg Wagner FMIC, Hotchkis sway bar, K&N CAI …work in progress…