Mmm, nah, it’s an attack. The Cato Institute says as much when it in an amicus brief it filed with the Supreme Court:

Chevron is unconstitutional for several reasons. It gives judicial power—the power to interpret the meaning of the law—to the administrative state within the Executive Branch. The Constitution, however, grants all judicial power to the Judicial Branch. Chevron is also unconstitutional because it biases the courts towards the agencies, stripping the judiciary of impartiality and denying litigants basic due process. But a third reason, and the focus of our brief, is that Chevron deference is ahistorical, arising not out of the original understanding of the Constitution but rather out of the administrative bloat of the New Deal era.

The explicit goal of elite conservatives is to undo the “administrative bloat of the New Deal era”, widely regarded as one of the best periods in American history and the foundation of many of the legal protections we have today.