Issue was resolved. The breakdown was with auto-formatting in Excel. When you export a list from SharePoint to Excel, Excel will auto-format URLs into hyperlinks.
I exported my SharePoint list without any values in the column that the URLs were supposed to go into and was trying to do a data refresh, which is why the hyperlinks were lost.
- Populate all URLs before exporting to Excel
Or, if you are updating URL values post-export:
- Update URL in SharePoint list (that is already linked to Excel)
- Open the table in Excel that is linked to PowerPivot
- Click on the 'Data' tab on the ribbon
- Click on the 'Refresh All' button on the 'Data' tab (URLs should now be in the Excel table as regular text)
- Click into the cell that contains the new URL value
- Click out of the cell
Excel should auto-format the URL to become a hyperlink once you click out of the cell. If this does not initialize the hyperlink auto-formatting, manually create hyperlinks for all URLs within the Excel table that is linked to PowerPivot. Power View will not interpret URLs as hyperlinks, it only interprets the data types as they are represented in the source data table.
Thanks @DavePaylor for the input