When importing an FBX file in an Action schematic, setting FBX Import Type to the option Link to Original File does not create a Geom node like Create Local Copy does, but rather creates an FBX Scene node.
You cannot perform the same operations on an FBX Scene node as on a Geom node.
If someone updates the linked FBX file, click Refresh to update the FBX Scene node in Action.
The options available in an FBX Scene node are also different from the ones found in a Geom node.