Prompted by the botched and buggy release of iOS 13, Apple has changed its internal development and testing processes for future operating system releases. The new changes will disable new or in-development features by default in OS versions under testing, allowing testers to better pinpoint problematic software.
https://www.notebookcheck.net/Apple-to-change-in-house-testing-process-for-iOS-14-development.443891.0.html