My experience with Nikon is they fiercely protect each country market. This includes grey imports which Nikon consider ANY of their products that are sent to a different country for service. Example - I was UK based until recently & Nikon will not even look at my UK purchased gear. Lens I bought from B&H was considered a grey import in UK. It not designed to be customer friendly but dealer friendly.
I expect all manufacturers are the same but I only have experience wit Nikon.