Thanks for the link to the script. We will make use of it.
I see that you were using it with the ACS/Geodatabase files. ACS/Geodatabase files are handy to use for the GIS person but not so much for the lay user working in Excel.
Our present application is tied to the csv download files from data.census.gov. These can be opened in Excel, saved, and linked to geography in ArcGIS Pro. Our Excel files have both the long and short field names but the named range only includes the short names. When the Excel file is joined in Pro ( or ArcMap) the files can't be edited and the alias values cannot be changed. I think it probably is an ESRI issue to allow the alias field to be edited.
Our particular application involves aggregating ACS/Decennial tract data to tract aggregates which we refer to as supertracts. We would like to provide long field descriptions both for the original tract data and that for the tract aggregates.
The solution might be to script the exporting of the linked Excel file to an ESRI database file followed by your script to change the alias values.