
To automatically deleting THE ONLY ORIGINALS
Wait.
At least, until you are sure things went smooth
Personnaly
I would create an EMPTY auto-add folder
Then
copy about 10 books there
Then see what you ended up with in Calibre, making adjustments as needed.
Preferences: Adding Books has a lot of useful features and settings.
It can add a Tag (eg 'New1'), Use Filename as Metadata or Internal Metadata...
Once you are satisfied... Then Offload/delete the originals