"they are finding out that the new [Kindle] models are mysteriously missing the download and transfer via USB option for purchased ebooks from the content page at Amazon."
The option to download and transfer via USB option is on Amazon.com website, and doesn't appear to be related to the new Kindles at all. So it's not clear to me what the new Kindles themselves are missing. I have a new Kindle Paperwhite Signature Edition that was just released, and I have books that I "acquired" (the word Amazon uses on their website) from Amazon on September 5 and September 16. I have the option to download and transfer them via USB on the website.
Can anyone clarify what option has actually been removed?