All paid addons include 1 year of support and updates. After the first year, the addon will still function in most cases, but updates will no longer be available unless renewed. This information is clearly stated on the addon’s landing page, just above the purchase button. The one-time purchase provides the addon along with support and updates for 1 year.
If you believe we mentioned updates beyond the initial year, could you please provide a screenshot showing this? You can also use our contact form to send the screenshot via email if that’s more convenient.
If you find that a paid addon no longer offers enough value to renew for updates, renewal is optional. The addon will continue to function unless it becomes incompatible with future versions of WordPress, PHP, etc. You can also delete the addon if it’s no longer needed. The free plugin will continue to work as usual.