Yes, but Microsoft really did do the missing integration of Kerberos V5 into the rest of the system (LDAP and the login system). MSFT started this work ("NT5") in 1995, just a bare few years after MIT published the first implementation of Kerberos V5 (though Kerberos IV came half a decade earlier still). That took MSFT ~5 years to complete, and they shipped this as Windows 2000.

Sun Microsystems, Inc. (RIP), completely failed to respond appropriately to that, and Active Directory ate Sun DS's lunch eventually.

LDAP, UofM, is better X.500. MIT and other schools were all connected over Kerberos from before, DoD? Hence the connection.