Nintendo is doing it like this to dodge the EU law for refunds. There is a window open which allows companies to not do refunds for digital products by stating they don't have to do it for digital content if the user has started downloading it. Nintendo is exploiting that by offering these preloads that make no sense, so technically the user has started downloading the digital product even though they can't use it for anything.
This is the reason why Norway is moving against Nintendo and tries to get them to abide to the intention of the law. Most likely Norway's push will end up pushing a small change to the law to close that window and stop future anti-consumer practices around it.