I understand your frustration with losing the folder previews after upgrading to Windows 11. I had the same problem when I jumped, which was a huge disappointment.
It's good to hear that you found an article that confirmed that folder previews are no longer available in Windows 11. I ended up switching back to Windows 10 because, for me, the loss of thumbnails on my folders was a deal breaker.
If you're also considering switching back to Windows 10, keep in mind that you can purchase a Windows 10 key. You can also look for
cheap windows 10 keys online.