Certificate Authority Authorization (CAA) is not listed directly in the provided options, but it is a relevant mechanism in the context of managing certificates and preventing issues similar to the one described.
However, based on the available choices, the Online Certificate Status Protocol (OCSP) comes closest to providing a viable solution. OCSP allows for real-time validation of a certificate's revocation status, which could mitigate the issue of users being locked out due to key pinning policies. It is a more modern and efficient alternative to Certificate Revocation Lists (CRLs), offering faster and more reliable certificate status checks. By implementing OCSP, the technician could ensure that clients receive timely updates on the revocation status of certificates, potentially avoiding the downtime caused by the key-pinning policy awaiting expiration.