The problem isn't that it's displaying an important security setting in a way that forces users to notice it. Kudos to Microsoft for finally having the courage to do so. Rather, the problem is that they haven't surfaced a method for expert users to disable the warning.
I think I found that method.
Run `gpedit.msc`. Navigate to:
Computer Policy > Administrative Templates > Windows Components > Bitlocker Drive Encryption > Operating System Drives
Set the following two policies to Disabled:
Allow Secure Boot for integrity validation
Use enhanced Boot Configuration Data validation profile
I think I found that method.
Run `gpedit.msc`. Navigate to:
Set the following two policies to Disabled: Should disappear the watermark.