Well, Ubisoft have decided to honour my order of my physical copy of The Adventures of Tintin using the promo code - I've just got the dispatch confirmation from them. Legally speaking, they could have cancelled it.

Lends credence to the idea that it was a deliberate marketing stunt.

Still works in France but they just raised everything that was 4.99€ or 9,99€ to 10,99€.