Sometimes a writer will try to make his point in a "fresh" manner, or gear it toward a particular audience, or tailor it to address one/set of particular concerns. Is this what's happening in the article quoted? I don't know; I'm just trying to help one see that every argument put forth requires due diligence from the reader. By reading (or listening) widely, one gains depth of perspective and may better judge where the best (to his ear) case is made, or where the "center" of a tradition is found.
The Confessional language provides a verbal starting point for agreement. If an author tries putting forth an argument that a certain term means something it manifestly doesn't, or tries to broaden or narrow the term unjustly, he should be challenged and corrected. His argument instituting novelty requires the most robust defense. The fact is there that the WCF uses the word "abrogated." When a law is abrogated, it is "abolished or annulled by formal/authoritative means" (a mashup of dictionary definitions found online).
So, the position taken by the WCF is that the Authority of heaven has set aside and removed the OT legal ceremony, and terms like "abolish" and "annul" are quite suitable as synonyms for "abrogate."
Now, what about the substance of the author's point, which seems to be that though the external forms of Siniatic ceremony are certainly removed: even so, the essence of those forms have a kind of continuance within the parameters of the New Covenant? Is this a valid observation? It seems reasonable to conclude, especially if one considers 1) that Covenant Theology asserts substantial continuity between OT religion in general, and NT religion under the gospel fulfillment of the Covenant of Grace; and 2) OT religion itself went through changes/elaborations from primitive institution of sacrifice through the glory-exhibition of the Levitical system.
If the institution of the Levitical system did not fundamentally change the religion of Abraham and the patriarchs, then it stands to reason that external forms may change without removal, alteration, or destruction of the core. But this then invites the question of whether we need to emphasize that the Law of Ceremony given to Moses isn't quite as UNDONE as is often said, when considering the spiritual reality. This seems unwise and not to be preferred. It might even seem to allow that the externals of Levitical ceremony were either too substantial (the signs were the things they signified); or paradoxically that they were insubstantial and inadequate even for their own time, and the New Covenant encourages reestablishment of as much outward ceremony as possible to exceed the glories of the former ceremonies.
The latter is observable in the pomp and circumstance typical of the hierarchical churches, be it Rome or EO, or (closer to us) in high church Anglicanism and some branches of Lutheranism. They all may not acknowledge their attempt to reinvigorate the Old Covenant ceremony for a New Covenant setting (some in fact do admit), but according to the strict Reformation this is the outcome of their efforts.
I conclude, we should not be hesitant to say that the Old Covenant ceremonies are done away. It seems much simpler to recognize the termination of the law as it was given to Moses; and to proceed to a defense of the abiding validity of the moral law (as it has existed since creation, not just since Sinai); the abrogation of OT ceremonies in toto; and the complete expiration of Israelite civil code legislation embedded in their constitution, the only obligation of which is any such law's connection to the timeless moral law (termed "general equity" or the embedded justice/fairness of any wholesome law).
