Hi Jack, I'm John!
If the case was already escalated after submitting the recovery form, it usually means it was forwarded to a higher-level account recovery team for manual review.
Replying to the confirmation email normally does not delay the process unless the email specifically says not to respond. In most cases, your reply just gets attached to the existing case.
Since your dad already received notifications about the security changes, that information may help during the investigation. I would just recommend waiting for the escalation team’s response first before submitting multiple new recovery requests, as repeated submissions can sometimes complicate the review process.
Should you need further information in the meantime, please let me know. Thanks!