https://credomag.com/article/natural-theology-and-van-til/
Classical Theology in this case is in reference to Aristotelian-driven Scholastic Theology and Thomism. This group (Credo Magazine) represents the Thomist revival in Reformed theology. It's sort of ironic that all of this is starting to really take off after the 2017 death of RC Sproul who championed it - but didn't live to see it.
That said, the issues are complicated as there are also strong Scholastic tendencies and tensions within Van Tillian circles as the commitment to Confessionalism is retained. The advocates of 'Classical Theology' have a point in that the Scholastic ethos was dominant at the time the confessions were produced in the 17th century.