In plain English
FAR 52.222-12, Contract Termination-Debarment, is a contract clause prescribed at FAR 22.407(a), most recently dated May 2014. The complete official text is reproduced below, verbatim, from GSA's published FAR source files.
Its text contains no sentence requiring insertion into subcontracts; see the flowdown section below for what that does and does not mean.
Does it flow down to subcontracts?
No flowdown mandate found in the clause text
We scanned the full clause text and found no sentence directing the contractor to insert this clause into subcontracts. That is a statement about the text, not legal advice: a prime contractor may still flow terms down contractually, an agency supplement (DFARS, VAAR, …) may add requirements, and clauses listed below (if any) may order this clause into subcontracts from the outside.
Where it's prescribed
As prescribed in 22.407(a), insert the following clause:
Prescribing reference: FAR 22.407(a).
The official text, verbatim
As prescribed in 22.407(a), insert the following clause:
Contract Termination-Debarment (May 2014)
A breach of the contract clauses entitled Construction Wage Rate Requirements, Contract Work Hours and Safety Standards-Overtime Compensation, Apprentices and Trainees, Payrolls and Basic Records, Compliance with Copeland Act Requirements, Subcontracts (Labor Standards), Compliance with Construction Wage Rate Requirements and Related Regulations, or Certification of Eligibility may be grounds for termination of the contract, and for debarment as a Contractor and subcontractor as provided in 29 CFR 5.12.
(End of clause)