Interesting one, i’d certainly contact MB live chat for that one.
My guess would be that MB wants you to tell them that pickup isn’t possible because the car is in the garage, and ask for a different appointment.
The main problem here is that the dealership can’t assess the car. Would be my guess anyway, but only MB can help you there.
Prior: SEAT Ateca Xcellence Lux 1.5 TSI DSG MY19, VW Golf GTE PHEV DSG MY23
Current: Hyundai Ioniq 6 Ultimate
Next: we'll see what's available in 2028.