I think the modern term for the clerisy is the Professional Managerial Class or “PMC” — and the definition of the working class has been expanded to include “service industry” workers.
Not sure that's accurate. The article suggests the "clerisy" operates largely outside the market system, e.g. doctors, lawyers, with the exception possibly being consultants. The PMC is very much a class in the market system.
The fact that a corporation has an exterior interface with the market doesn't change that most people in it don't deal with the market day-to-day. Even those who do form that interface are relatively insulated from it: a market analyst working to set prices still is evaluated by an internal bureaucracy, not the market itself. Only people in sales really end up exposed to the market because it's so easy to come up with a metric of their performance that's legible to the interior bureaucracy.