They're removing the button to download the book to your computer from their website.
If you buy a Kindle book, or borrow a digital book from your library, you could then use the "Download and Transfer with USB" button to get the file on your device. You'd then use Calibre and the DeDRM plugin to remove the DRM.
If you buy a Kindle book, or borrow a digital book from your library, you could then use the "Download and Transfer with USB" button to get the file on your device. You'd then use Calibre and the DeDRM plugin to remove the DRM.