It appears Animal Crossing: New Horizons players could have the option to save their game data to the cloud if they are a Switch Online subscriber.
This is according to Nintendo Japan, which states the company is planning a cloud save option for Animal Crossing: New Horizons players.
At present, the option is not available, but Nintendo says it is "planning to have a save backup function for this software, available to Nintendo Switch Online users." When it will be available is unconfirmed, but Nintendo promises to keep folks updated (thanks, resetera).
Here's the quote using Google Translate:
"We are considering a function to back up saved data in a unique form of this software in case of failure, loss or theft of the Nintendo Switch itself. Use of this function is limited to Nintendo Switch Online subscribers. Correspondence time is undecided. We will inform you as soon as the time is decided."
The ability to save your game in some fashion other than on your console is good news because as it stands now, you won't be able to transfer save data from one Switch to another.
This was confirmed on the back of the German game box (via reddit) and confirmed by the Japanese site. It states: "The save data of this software does not support "moving user" or "moving save data", so you cannot move save data to another main unit."https://youtu.be/nCwVTCxm29c
But, should Nintendo implement the ability to save the game using Switch Online, that's less worrisome should your system break or happen to be stolen. You won't lose the many, many hours you put into the game. Hopefully, Nintendo will announce its plans soon considering the game releases March 20.
It's thought the reason for the inability to transfer saves or the game from one Switch to another has to do with only one island allowed per console due to the fact multiple user accounts will share the same island.