Q. How can I view the key protectors for a shielded VM?

A. To check the key protectors and certificates used for a shielded VM use the following PowerShell:

$kp = Get-VMKeyProtector -VMName ShieldedVM
$hgskp = ConvertTo-HgsKeyProtector $kp
$hgskp.Owner | fl SigningCertificate, EncryptionCertificate

If you have additional guardians these could be viewed by looking at $hgskp.Guardians.