Lowry Digital Images hasn’t existed for ages now, since 2010 I think?
I do know that Disney did get a print when making Rogue One, they wanted it as reference to make sure they matched the look of the original Star Wars. It may have come from the LoC.
If the request was more recent than Rogue One, it might be for some other purpose though, which would be interesting.
This story made the rounds before RO was released. Makes sense then. Though it’s hard to believe Lucasfilm doesn’t have prints on hand or something else better quality than the copyright deposit.