Just looked this up. It looks like the new generation just shows up as an MTP device instead of an external drive. That doesn’t stop sideloading books onto the device, it works as before.
However, they’ve seemingly stopped allowing the “download and transfer” option for Amazon-bought books, which was an easy way to get them into Calibre and remove their DRM. So that’s something to keep in mind for sure if you want to buy ebooks from Amazon.
I’m 100% sure they exist and I’m 99.9% sure there won’t be any contact over the next 10 years. It’s entirely possible there will never be, though I do hope otherwise.