I did in fact miss the purported locking of the Apple ID. It appears as though accounts can be locked under certain circumstances[1]. So the Apple ID was locke

I did in fact miss the purported locking of the Apple ID. It appears as though accounts can be locked under certain circumstances[1]. So the Apple ID was locked, presumably due to many accidental or malicious attempts to log in to the account. The account owner is then left having to perform account recovery, which is where the security questions and access to the email address's inbox come into play. [1] https://support.apple.com/en-us/HT204106 https://support.apple.com/en-us/HT204106