From what the article says, that's doesn't appear to be true.
In order to download and transfer Kindle books from the Library, I have to first add them to "My Content" on Amazon, then from the Amazon interface click "Download & Transfer via USB". That's the only way to access the AZW3 files that get moved over to the Kindle.
In order to download and transfer Kindle books from the Library, I have to first add them to "My Content" on Amazon, then from the Amazon interface click "Download & Transfer via USB". That's the only way to access the AZW3 files that get moved over to the Kindle.