They cannot scan the books then resell them or donate them under current US copyright law. It’s not clear to me that they could warehouse them if they wanted. In the recent Bartz v Anthropic case the judge ruled this destruction as legal, saying
> The print original was destroyed. One replaced the other.
So that there was still only one “copy” of the book. This is in compliance with the DMCA. You can make a personal digital copy of a work but then you cannot resell the hard copy and keep the digital one. Same principle applies here.
Nowhere in this description did it require destruction of the physical book. This is being done because it's easier to scan a shucked book, and this explanation is circulating because it's easier to blame it on the law and that pesky meddling government.