Old Covenant Revoked?

[HMiS]

The New Covenant superseded the Old Covenant, the observation of which laws, have no salutary value anymore - and by those knowing Christ, are mortal sin probably even.

They never had any salutary value anyway according to the Apostle. Faith and Hope in and love for Christ by His Grace alone saves in His Church.

Their observation (of these laws) was not Redeeming or propitiatory or directly salvific in the definite sense, but of course the Lord God demanded their observation as proof of their fidelity and thus to prove their openness to His salvation.

Of course the works of the Law themselves alone cannot redeem, but they were proof and expression of faithfulness to God's promise.