I doubt hornady even handles the rebates.
Prolly a 3rd partly processor.
Year or so ago i did a rebate on contacts i ordered.
It was processed by someone other than the manufacturer.
Pretty easy process. Take a pic of bar code and receipt.
Same with Sig when they were doing the buy a p365 and get $xxx Sig Store credit.
That's my take as well. Every rebate I've ever sent in went to a 3rd party outfit.