Huh. 🤔
I haven't kept up with whatever Microsoft is doing, but my only thought is possibly it's using the TPM in some way to accomplish this?
IIRC, that's what all their FDE is based on, which is great for attackers who steal the whole computer and not just the hard drive.
I have many thoughts on FDE, something you have/know, and hardware security. 😁 They are generally independent of any operating system or implementation.