Do you have a source for that?
BitLocker FAQ says
How can the recovery password and recovery key be stored?
BitLocker Drive Encryption allows you to manually encrypt a specific drive or drives on a device running Windows Pro, Enterprise, or Education edition.
uszo165@futurology.today 5 days ago
My source was my own experience that my Windows 11 volume is encrypted and I have never been asked about key upload. So I assumed this happens automatically. I guess I am mistaken. I did not consider that my installation has no online Microsoft account. But since Windows is closed source no one knows for sure what gets uploaded.