Unreliable airspeed has been called unreliable airspeed for many years. It is not a new term, neither is the abbreviation.
I recall checklists called "unreliable airspeed" from at least the early 90's, possibly the late 80's, and expanded checklists and explanatory material with the heading "speed control with unreliable airspeed".
The expanded checklists and explanatory material were more detailed in the A300 days than for later models, particularly concerning the various failure modes and effect on indications and systems.