This is semantic quibbling, just pretend they're saying "the professional managerial sub-class". Honestly at this stage of capitalism when so much capital has been alienated from actual capitalists into the hands of hired managers, it's not the worst thing to discuss this group (which is a distinct and influential group in our society)

And I know trotsky developed the term "labor aristocracy" which is similar, but when I hear that I think of engineers, not corporate managers and their lackeys