Nintendo has detailed the Nintendo Switch paid online service that is launching in September and they have confirmed that the Switch will be finally be getting online cloud save backups.
Only the Japanese website has been updated so far (and it’s quite hard to translate due to the build of the website), but one of the main features that I’ve been able to confirm so far is internet save backups.
“We will store save data in the main body via the Internet. Data can be prevented from being lost even in the event of a failure. (Except for some software)”
It looks like it will be a paid feature, which is to be expected and exactly how it is for both PlayStation 4 and Xbox One.