What happens after the Datylon for Illustrator license expires?

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

When your trial version or annual subscription of Datylon for Illustrator expires, and even without the plug-in installed, charts created with Datylon can still be edited in Adobe Illustrator as regular .svg objects. You just can't use the Datylon features and functionality. 

All charts can be viewed, moved and scaled, or exported just like any other .svg object at any time.

After expanding and ungrouping the chart, the different components can still be manipulated within Illustrator.  See this article for more details about ungrouping a Datylon Chart.