Amazon has a new help page up on their website regarding software security updates for Kindle ereaders where they guarantee that Kindles will receive security updates for at least four years after the device is sold on their website as a current model.
There’s also a new entry on the Manage Your Devices page at Amazon that indicates how long security updates are available for each of your Kindles.
For example, current models are included through 2025 (the big question is are they going to change it to 2026 in a few months when 2022 hits or are they going to release a new lineup of Kindles soon?).
On older models like the Kindle Paperwhite 3 and Kindle Voyage, the page indicates security updates will be included through 2022. A lot of the older models are already past the cutoff date, but those models haven’t been receiving updates for a long time anyway.
Amazon implies they will still try to provide security updates beyond that time, but there’s no guarantee past four years after they’ve stopped selling a particular model.
See the help page below for more details: