If they did a ECU remap (likely) coupled with some hw changes to the engine (maybe, maybe not), they would likely have at least suspected something.

Like, I can tune my Lancer Evo, with stock parts, to around 360 chp / 290 whp from 291 chp / 220 whp. This will put more strain on the parts, to nuke the little gas mileage, up the emissions (no CARB), and void the warranty on the drivetrain. In order to do that the ECU needs to be flash (by say cobbs tuning) and if there was a cheating thing they will need to be aware of it or else it'd be likely gone in the flash.

If I was to put on new parts and make it go even more... Then for sure you need a new tune to make it actually work properly.

Nobody is going with Porsche for fuel economy but nobody is expecting to have their Porsche lose power due to a recall either. It's a premium badge, I expect them to dot more of the I's and cross more of the T's when I pay that extra $20-$40kk for a Porsche branded Touareg.