I cannot find an regulation, instruction, etc. that specifically spells out and Acquisition Review Board. Is there one?
In short, the answer is no, there is not one.
Caveat: this answer is for DoD only (GSA and DHS do have regulatory and statutory language for an acquisition review board).
For context I needed to read your manual, but all I could find was DCMA-PTM 18-006 dated Jan 13, 2019. It does not appear that it is related to any of the potential reviews that occur during major weapon or cyber systems acquisitions. It appears to focus on actions above the simplified acquisition threshold (SAT).
The DoD Instructions associated with the Adaptive Acquisition Framework (e.g. DODI 5000.02T, DODI 5000.74, etc.) have many instances where boards and reviews are required, but none of them are specifically called an “Acquisition Review Board”. Similarly, Joint Publication 4-10 Operational Contract Support used to describe the function of a JARB “Joint Acquisition Requirements Board”, but they have since changed terminology to Joint Requirements Review Boards.
Bottom-line: for the vast majority of DoD the term “Acquisition Review Board” is a generic or colloquial name for an internal controls process associated with an acquisition. The FAR and DFARS give high level guidance on when reviews and approvals are needed. See FAR 1.602-1(b) and the phrase “clearances and approvals” and see DFARS 201.170 with its associated PGI. Note, the Army FAR Supplement does use the phrase “Acquisition Review Board” at AFARS Appendix BB – 204. However, a review of that reveals the context is very similar to the DCMA guidance referenced above.