@jessamyn @overholt I think that sometime in the 2010s they shifted to sending a lot of books to China and the Philippines for scanning.
I'm going off of this DH project, which looked at the metadata attached to scanned IA items in addition to talking to scanning staff: https://scanninglabor.github.io/IAScanningLabor/discussion.html
I saw these folks present at a conference, and recall them saying the books were being destroyed rather than sent back across the Pacific—but can't find confirmation