In order to create a consistent experience for managing and viewing files across Drive, Google has changed the “Add to My Drive” option to “Add shortcut to Drive" so that files are stored in a single rather than multiple locations.
The new way to view a shared file or folder is by using Shortcuts in Drive.
Shortcuts in Drive make it easier to organize content and point users to relevant information and files across various drives. Shortcuts are pointers to content that can be stored in another folder or drive, a shared drive, or an individual user's “My Drive.”
Shortcuts in Drive also replaces using the keystroke shift+z to add a file to multiple folders.
Shortcuts in Drive also replaces using the keystroke shift+z to add a file to multiple folders.
Shortcuts are visible to anyone who has access to the folder or drive containing the shortcut. Even if someone can see the shortcut, however, they can only open it if they have the appropriate access to the original file or folder.
Starting on September 30, 2020, it will no longer be possible to place a file in multiple folders in My Drive. Going forward, every file will live in a single location. And after September 30, 2020, all files already living in multiple locations in My Drive will gradually be migrated to shortcuts.
Use Google's Help Center to learn more about using shortcuts in Google Drive.