How do you know the same thing in that picture would come out of Alcantara?
How do you know the same wouldn't happen with Alcantara? My guess is the detailers who worked on your car didn't know what they were doing, especially if they abraded the premium textile trying to remove the stain.
From personal experience and what I've read online, most synthetic fabrics respond to stains in similar ways because they're mostly made with polyester/polyurethane. If something will come out of Alcantara after wiping it down with water, it'll likely do the same in premium textile.
If it's not water based and doesn't come out with water, then it's probably an oil, which should come out with ethanol/*chrloroethylene/etc, and if it's an ink, it'll probably come out with Acetone, although regardless of the material/stain/solvent I would definitely test whatever I was using on someplace out of the way first.
VWVortex.com - How to clean beige headliner?
Dry cleaning - Wikipedia