Hi Gerry81,
Cyclone® IV still active and available. Anyhow, the life cycle is depending on its order volume and they are considered as old devices. Hence they are not recommended for new design as they might be EOL soon.
You can subscribe to our customer notification mailing list at the below link so that you can be notified when an Altera device is going to be discontinued.
https://www.intel.com/content/www/us/en/programmable/support/support-resources/knowledge-base/soluti...
Generally, you are recommended to use the newest Cyclone devices for your design. There are low-end versions of the Cyclone V E and the Cyclone 10 LP that can consider as well. Please check the following link:
https://www.intel.com/content/www/us/en/products/programmable/cyclone-series.html
Regards,
Fakhrul