A change of vector is a shear. Period. If you change your track relative to a steady wind, you are introducing a shear through the change in vector, your inertial mass has to accelerate or decelerate. That shows up as an airspeed change.
Isn't is true that "track" is ground referenced? How is a change of track (ground referenced) of any significance at all to the movement of the aircraft in a uniform airmass (airmass referenced).