Recently Nintendo confirmed that its coupon offer for games Nintendo Switch will not be available in North America again but will remain present in Europe
Y Japan; and maybe it extends to other territories.
This is what a recent maintenance notice suggests for the eShop from Nintendo Switch
for Hong Kong, in which it indicates that the reason is the discount coupons for titles. Although it has not been confirmed, it seems that you will soon be able to take advantage of this mechanic also from this virtual store, if you have the HKD