In DHL the link to get tax documents is already broken for a year or so, so I cannot get VAT back on DHL shipments.
With FedEx I can but it's a manual process of screenshotting a bank transaction and emailing a specific email address with a shipping number.
When tariffs started all the servers of the shipping companies went down.
So I highly doubt they will just do some computer magic.
From experience I assume they will "accidentally" run into all kinds of technical difficulties making it a 274 step process to get the money back.
For scale: Shopify, a software company by heart, with 170bn market cap and 3500 engineers employed, does not have native VAT support, required in the Europe which accounts for 15-20% of their revenue. All they would have to do to support this is add a checkout field "VAT number" that shows up on a pdf invoice.
So to assume a shipping company will just work some computer magic is really far fetched. The FedEx page only lets you login after you refresh the page exactly once already for more than a year.