I mean, you're citing goodereader.com as though that's somehow an authoritative source and not just a blog by a guy who likes ereaders, but has no special legal knowledge.
Much more useful would have been if you had linked to an archive of the original Kindle Store Terms of Use, which state:
> Use of Digital Content. Upon your payment of the applicable fees set by Amazon, Amazon grants you the non-exclusive right to keep a permanent copy of the applicable Digital Content and to view, use, and display such Digital Content an unlimited number of times, solely on the Device or as authorized by Amazon as part of the Service and solely for your personal, non-commercial use. Digital Content will be deemed licensed to you by Amazon under this Agreement unless otherwise expressly provided by Amazon.[0] (emphasis mine)
Notice that "or as authorized by Amazon" is part of the clause with "solely on the device," not a separate clause that somehow might be interpreted to apply to the "right to keep a permanent copy" part.
Does it also say that it is considered licensed to you? Sure. But the "license" is the "right to keep a permanent copy."
It's one thing for Amazon to say, "Shit, we sold you a book we weren't authorized to sell. We have to undo the whole transaction." It's quite another to do what the GGGGGGGP comment (I didn't count the G's) is complaining about and delete your permanent copy of a book for which they did validly sell you a license to keep a permanent copy.
Amazon has meaningfully changed the license agreement now. In 2025, it says:
> Use of Kindle Content. Kindle Content is licensed, not sold, to you by the Content Provider. Upon your download or access of Kindle Content and payment of any applicable fees (including applicable taxes), the Content Provider grants you subject to the terms of this Agreement, including without limitation those in “Changes to Service; Amendments” below, a non-exclusive right to view, use, and display such Kindle Content (for Subscription Content, only as long as you remain an active member of the underlying membership or subscription program), solely through Kindle Software or as otherwise permitted as part of the Service, solely on the number of Supported Devices specified in the Kindle Store, and solely for your personal, non-commercial use. Content Provider may include additional terms for use within its Kindle Content. Those terms will also apply, but this Agreement will govern in the event of a conflict. Some Kindle Content, such as interactive or highly formatted content, may not be available to you on all Kindle Software.[1]
They've eliminated the right to keep a permanent copy that was originally part of the license sold. That change matters. Deleting content sold under that license is a violation of the terms of the agreement on their part.
[0] https://web.archive.org/web/20110109000847/http://www.amazon...
[1]https://www.amazon.com/gp/help/customer/display.html?nodeId=...