Progressive Date Columns

If you want to still just query one file, but have it dynamically select the latest one (based on last created or some other datetime metadata column), then this should work as you intend ONLY IF you inject some additional steps up front that reads the files in the folder and then connects to the latest one.

Once you query to get latest file and download (edit: by "download" I mean get it into Power Query, e.g. Web.Contents("<some url to a file online>")) the binary (how you do that is specific to the data source - e.g. SharePoint will look a bit different than your desktop files and at the very least requires a different connector to query folder contents and get xlsx binary), then the steps as provided should work.

If, however, you want to query a folder, cobmine all xlsx and perform the above, then it's sort of similar to what I described above (step 1: query folder, step 2: get single file binary, step 3: perform transformation provided in solution), except you need to do something a little different at step at 2: 2a) get table/list of file binaries, 2b) parse, normalize, and combine into one table.