Quite a few of these aren't EU members, some aren't even in Europe; do we know why they were added? e.g.: Switzerland or United Kingdom; but also Oman or United Arab Emirates.
It's easier for Nintendo of Europe to switch over everyone than to stock and supply 2 versions of every product. Also I'd bet most of their sales come from the EU countries where the replaceable battery requirement is forcing this new SKU deployment anyways.
That's probably because Iceland is not an official Sales-territory of Nintendo, it's handled by Bergsala AB, a swedish distributor which serves the market there.