Largely not, though given that there's an entire field basically devoted to this (Critical Discourse Analysis), it's not exactly done in secret.

It's also not the exclusive purview of the academically-inclined left. The right in the U.S. has their own flavor, wherein they intentionally add--often just by flat-out lying about it--massive negative moral judgment to unfamiliar terms used by the left, taking advantage of the lack of familiarity to impose their own judgment.

Thus, "critical race theory" becomes a term broadly associated with morally degenerate countercultural thought, so when people hear the term they pick up the right's implanted moral judgment*.

Either way, the outcome is the same: much of the rhetorical work is dishonest manipulation of moral outrage, by counting on the embedded judgment associated with terms (whether well-known and widely accepted, but meant to apply to a different context; or poorly-known and rapidly filled-in to be that which is rhetorically favorable).

* Critical Race Theory is epistemologically bankrupt in pratice, as is all Critical Theory, due to how poorly the underlying method and assumptions work with human psychology: it discards essential safeguards and emphasizes some of our worst cognitive traits. But as with most human endeavors that have an epistemologically bankrupt component, actual CRT has been a mix of good and bad, and rather than burning it at the stake we should clip out the good parts and put them on sound footing.