Earlier today, Nintendo finally revealed all the details regarding the Nintendo Switch Online Service, also confirming that cloud saves will also be available. Sadly, it seems like not all software will be compatible with the feature.
The Official Japanese and UK Nintendo websites mention in the cloud saves description that not all titles will be compatible with the feature. It's likely that games with online multiplayer modes, such as the upcoming new Pokemon games, will not be compatible with the cloud saves feature to prevent cheating and tampering with save files.
Nintendo also confirmed today that all Nintendo Switch Online Subscribers will have access to a compilation of classic NES games, with some of them getting online multiplayer.
Subscribers will have access to NES – Nintendo Switch Online, a compilation of classic NES games. The collection will initially include 20 games, with more added on a regular basis. At launch, previously announced games Balloon Fight, Dr. Mario and Super Mario Bros. 3 will be joined by Donkey Kong, Ice Climber, The Legend of Zelda, Mario Bros., Soccer, Super Mario Bros. and Tennis. An additional 10 launch games will be announced in the future.
For the first time ever, players will be able to enjoy these classic NES games online. Depending on the game, players can engage in online competitive or co-op multiplayer, or take turns controlling the action. Friends can even watch each other play single-player games online, and “pass the controller” at any time. Every classic NES game will support voice chat via the Nintendo Switch Online smartphone app. It will also be possible to play these games offline.