According to NIST SP 800-37 Rev 2, which role has a primary responsibility to report the security status of the information system to the authorizing official (OA) and other appropriate…

The Information System Security Officer (ISSO) supports system-specific security and reporting but does not hold primary responsibility for common control status reporting to the AO.

An Independent Assessor's role is to evaluate controls, not to provide ongoing operational status reports of common controls to the AO.

NIST SP 800-37 Rev 2 clearly assigns the Common Control Provider the primary responsibility for continuous monitoring of the security and privacy posture of the common controls they provide, and for reporting this status to the Authorizing Official (AO) and other appropriate organizational officials.

A Senior Information Assurance Officer (SIAO) has a broader oversight role but is not typically responsible for the specific ongoing status reporting of individual common controls to the AO.