@forceofhabit @molly0xfff
My understanding is that the case is about whether it is "fair use" to share digital scans of their collection of copyrighted physical books as long as they only allowed one user to view the scan at a time (similar to lending physical books). Their collection of public domain materials should be unaffected. However, lawsuits are expensive.
That said, I recently used the IA lending library to access a scan of an old copyrighted book to research whether another work is public domain (it is!). This would not have been possible otherwise.