GUID fields are omitted from Microsoft Access database tables when converted to file geodatabase tables using the Import Access Tables tool.

Solución alternativa

1. Launch ArcGIS Pro.
2. Navigate to the Insert ribbon tab > Connections > Database > New OLE DB Connection.
3. In the window that opens up, select Microsoft Office 12.0 Access Database Engine OLE DB Provider > Click Next.
4. In the Connection window that opens next, add complete path to the Access Database in the Data Source section.
5. Keep everything else as default and click OK.
6. Open the Catalog pane, expand Databases and the new OLE DB database connection will be listed.
7. Expand the database connection made previously and right click on the table of interest.
8. Export this table to a file geodatabase using the Table to Geodatabase tool and observe that all the fields are being retained.

Pasos para reproducir