Digital records are actually far, far more vulnerable than paper copies. How often have you suffered digital data loss? How many storage media do you have for which suitable machines are now extinct? Large archives depend on large computers and constant data migration and they too are vulnerable.

Originals may also have information for researchers that will not be available in a photo.

Finally, donors should have been offered the chance to retrieve their paper files and deposit them in a location where they will be preserved according to the specifications of the gift.

I am sure many librarians and archivists as well as researchers will regard this as a rash decision. This is an untested experiment.