This response is based on the information provided.  We suggest you discuss with your contracting team, program manager and/or legal department as appropriate.

This does not fall under FAR subpart 32.8, Assignment of Claims.  In The assignment of claims relates to the prime contractor assigning payment due it to a party other than itself that is a bank, trust company, or other financing institution, including any Federal lending agency.  The arrangement you are describing is a specific term being negotiated between the prime and one of its subcontractors.  There is no pertinent information in the DFARS, AFARS, or AFFARS (we are assuming from the area code the question comes from the USA or USAF).