We do not use RichTextBox, so there is no risk for CONNECTION client/Licensing using the library since we do not use the part that has a problem.
"If a project is not using the RichTextBox, the application is unaffected by this issue."
Here is the official Telerik documentation:
CONNECTION client does not allow the following Telerik components:
The future release of the CONNECTION client/License service will remove the reference to Telerik