They never published full works of any material covered by copyright. They did and do publish excerpts, which every court has said is well within fair use.
Full text works where the copyright has expired (and the formerly protected work became publicly owned) has been published, and will continue to be published by a wide variety of publishers.
If this is truly the case, then websites really have no right objecting to people copying and pasting whole articles online
Since those articles are protected by copyright for the lifetime of the author plus 70 years, they can not be reproduced for commercial purposes. The Internet Wayback machine, on archive.org, is a legal case waiting to happen as they do republish entire articles without excerpting - their best defense is they don't monetize it. But they are without a doubt the largest publisher of copyrighted works in the world (followed by Google through page caching.)
As for transformative - going from print to digital can be seen as a derivative work as it has transformed it into a new media. But that doesn't work for commercial use of publishing the entire text. (Lexus-Nexus pays quite a bit for the rights to republish full text work.) Scanning it and placing it into a referential database is transformative and of course the courts approved it.
If you read the article at the link i provided you will see the article states ‘frequently out of print and out of copywrite-” Indicating ‘not always’ out of print or copywrite- and like i said in earlier post- there is no mention about exerts, and there are indications that the issue is about whole books being published- I don’t see writers being upset over having an excerpt being published to showcase their writing style and writing abilities- but i do see them upset if their books are being copied word for word in whole-