[OtinG]

No clue what deregistering a device and reregistering it will do as far as downloaded material, but I will say that it pays to go to the web page at Amazon to view and edit your devices every now and then. A couple of weeks ago I went to make sure I had deregistered a couple of devices I was selling. I was amazed at how many iOS and other devices were listed under my Kindle devices and apps. Every device I have ever registered for Kindle services was listed there, and they were virtually impossible to tell which was which by glancing at the names because Amazon uses a naming scheme similar to "5th iOS Kindle app". You have to click on each one in the list and get the details to try and figure out which device the list item is referring to. I took several minutes to go through and delete all the old and no longer used devices (Kindles, Android tablets, iOS iPhones and iPads) from the list, then renamed all the still active devices to something that made sense like "Kindle App on iPhone XR" and "Kindle App on iPad Pro 9.7".