Is this a bug in the Active Directory module?

objectClass is a multi-value property, but no matter what, it only returns 'user'. The same happens for Get-ADObject and I suspect any query of the objectClass property for any object will only return one value (maybe the last in the multi-value list?).

E:\(Get-ADUser -LDAPFilter '(&(objectClass=top)(name=xxxx))').objectClass
user
E:\(Get-ADUser -LDAPFilter '(&(objectClass=person)(name=xxxx))').objectClass
user
E:\(Get-ADUser -LDAPFilter '(&(objectClass=posixAccount)(name=xxxx))').objectClass
user