Yes. All the projects created in KineMaster 5.0 or higher will be deleted if you delete (uninstall) the KineMaster app. Clearing app data in your device settings will also remove all of your KineMaster projects.
Occasionally, some devices may encounter issues related to crashes, lag, or unrecognized subscriptions. Do not delete (uninstall) KineMaster or clear app data. Please reset KineMaster using Reset in the in-app Settings option (KineMaster >> Settings >> Reset).