With ArcGIS Desktop being going away and we all need to import all of the MXD files to Pro using import tool but what if you have so many MXD that you need to do import ?
Is there a script to do that that will allowed me to use the script to tell Pro to import many of MXD along with the Data Source to their current data souce ? What about ArcMap Symbology from ArcMap ? etc ...
Lastly, What happens if the ArcGIS Desktop is uninstall from your agency and what happens with the MXD file ?
Looks like someone wrote a script to do this:
https://community.esri.com/t5/python-questions/arcpy-import-mxd-into-arcgis-pro-project/td-p/1236541
Regarding your question about symbology, symbols are based on fonts, and the Esri fonts on which the ArcMap symbols are based hae been imported to ArcGIS Pro at this path:
C:\Program Files\ArcGIS\Pro\Resources\Fonts
If you have created custom symbols, or used fonts that were not originally installed with ArcMap, those symbols will draw with the system defaults when the MXDs are imported to ArcGIS Pro.
If ArcGIS Desktop is uninstalled from your computers you will not longer be able to open the ArcMap .MXD files in the native application but they can still be imported into ArcGIS Pro.