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

"FAR 32.703-3 Contracts crossing fiscal years.

...  (b) The head of an executive agency, except NASA, may enter into a contract, exercise an option, or place an order under a contract for severable services for a period that begins in one fiscal year and ends in the next fiscal year if the period of the contract awarded, option exercised, or order placed does not exceed one year ( 10 U.S.C.2410a and 41 U.S.C.3902). Funds made available for a fiscal year may be obligated for the total amount of an action entered into under this authority."

We believe the question you pose is, "Can we fund the REA for the wage determination for FY 22 work with FY23 0130 (O&M) even though the FY22 work was funded with FY22 0130 (O&M) appropriations.

You state the contract will not be modified until FY23.  At that point you will not have obligatable (unexpired) FY22 funds.

You can use the FY23 funds for the wage determination adjustment.