When Nintendo announced that the end of Switch Online subscription would mean the end of their save files, fans got rightfully upset. The company apparently changed policy and will allow the saves to stay for 180 days post subscription.
Players will apparently have 180 days or six months after their subscription ends in order to resubscribe and recover save files. With that in mind, it is important that the users understand that they will not be able to access the save files if they are not subscribed at the time of attempting to do so.
The situation could easily be seen as Nintendo holding the save files hostage, but at least it's some progress from straight up deleting them once the subscription ends. This way, Nintendo brought the standards of their subscription service to that of Sony's, where PS Plus subscribers also have a six month grace period.
Microsoft is still ahead of both companies in that department though, as they offer Xbox One users the cloud saves for free even if they don't subscribe to Xbox Live Gold. These days it just seems that Microsoft and Sony are going back and forth by making the opponent's flaws their own selling point, as Microsoft requires paid subscription from players if they want to run Fortnite, a game that's free otherwise.
Cloud saving is a decent commodity to have, but it will not be available for all the games on Switch. Pokemon: Let's Go - both Pikachu and Eevee, Dark Souls: Remastered, FIFA 19 and a few other titles cloud saving.
On the other hand, Nintendo stated that "The vast majority of Nintendo Switch games will support Save Data Cloud backup", while explaining that some games will not feature cloud saving due to ability to reroll to an earlier state of the game, which would allow players to get back any items they traded or regain higher multiplayer ranking.