There are only a lot of guesses of what happens when you switch from a digital to physical game card version of a Nintendo Switch game, e.g. at the Nintendo forum here: https://en-americas-support.nintendo.com/app/social/questions/detail/qid/71828/~/go-from-digital-game-to-physical/comment/14407
That is correct. Simply enter the System Settings screen from the Nintendo Switch Main Menu, head down to Data Management, then “Manage Software”. When you scroll through the options regarding managing the software in question, you should see an option which states that the software and the game icon will be deleted, but to delete the Save Data, you’ll have to access another section of the Data Management screen.
Created 12/29/2017 05:33 PM
2) You select to “Archive”. Then on the home screen in the game selector, the game icon will be marked on the top with the “Cloud” icon. When you then insert the Game card, it will ask if you wanna do an update download maybe (Say yes) then the game will start loading from the Game Card and the icon above the game change from the cloud Icon to the”Game Card icon”
3) When you remove the game card again, the icon will change to the cloud icon again. Means you can switch between game card and cloud version all the time. 🙂