Migrating from Thy Phone to Microsoft Phone Link on Windows 11
Reset Thy Phone
You can either go to Settings in Thy Phone and select "Reset Connection" to remove the link with your phone.

Uninstall
Or uninstall Thy Phone which will also unregister it.
Ongoing Support
Thy Phone will continue to support calls and audio sharing on other Bluetooth enabled phone devices which are still not supported by Microsoft Phone Link such as Nokia, Windows Phone, Blackberry etc. With this new focus a future update for Windows 11 will remove the notifications functionality and streamline the user interface for these supported device types. The existing version will continue to be available on Windows 10 and support iPhone including Notifications.