Yes, it should be scanned at the next sorting centre, although... you never know.

The risk of course also exists for domestic parcels posted in a red street mailbox.

Personally, I have always received everything posted in a red street mailbox. The tracking just didn't update until the parcel got scanned at the next sorting centre, and on a couple of occasions it only got scanned the day it was on board for delivery, but I always got everything.