There is always a step which involve to email the domain when a domain update its information with the registrar. In this case, facebook.com and registrarsafe.com are managed by the same NS. You need these NS to query the MX to send that update approval by email and unblock the registrar update. Glue records are more for performance than to make that loop. I'm maybe missing something but, hopefully they won't need to send an email to fix this issue.