What happens after the Datylon for Illustrator license expires?

No work is lost when your Datylon for Illustrator trial or subscription expires.

The expiration or uninstall of the Datylon for Illustrator plugin does not impact the Datylon charts in your Illustrator documents. Even though they cannot be edited anymore, it's important to note that they still remain fully functional and retain their visual integrity. This means that all the data and the charts themselves can still be manipulated and modified at a later stage, as long as you have an active subscription to Datylon for Illustrator.

If you want to edit the charts when your trial version or subscription of Datylon for Illustrator expires, or even without the plug-in installed, you need to expand the charts in Illustrator (Illustrator menu > Object > Expand).

However, after expanding the chart, the link with the data is lost and can never be retrieved.  See this article for more details about ungrouping a Datylon Chart.