The last, final release of the 380.xx series is now available for all supported models.
People using an RT-N66U or RT-AC66U and wishing to gain continued updates are urged to consider switching to @john9527 's fork, which is still in active development.
For those using any of the other supported models, it is highly recommended to switch to the new 384.xx code that is currently the actively maintained branch. This will ensure you continue to get security updates as they get released. Also note that Trend Micro will eventually discontinue support for signature updates for their older engine used by the 380.xx series.
The focus of this release was to address a couple of security-related issues. Note that the latest security fixes for AiCloud are not included, as for most models these are only available for newer firmware code - backporting them to the 380.xx series would be too much work considering this code base is now at the end of road.
Please consult the changelog for details as to what was changed.
Downloads are here.
Changelog is here.