Hi,
In this case, that registry key no longer has any effect in Windows 11 26H2; you can use free third-party programs to switch back to the old version.
https://apps.microsoft.com/detail/xp9cjb1mrgl3c3?hl=en-US&gl=US
Please consider rating the question (by accepting the answer or otherwise) and visiting the Microsoft Q&A community if you have any further questions.
Thanks.