HazelNuts39.
Yes, it is. I could have been more precise, sorry, but here is my reference.
"...In cruise at Mach 0.8, the margin between the flight AoA of the STALL WARNING is of the order of 1.5 degrees, but the STALL WARNING speed displayed on the air speed tape (in ALTERNATE or DIRECT LAW) will be around 40 knots below the actual speed. The value of the angle of Attack is not displayed directly to the pilots. The angle of attack is the parameter that allows the STALL WARNING to be triggered, but the activation threshold of this warnng is indicated by a marker on the airspeed tape. When the ADR are rejected by the flight control computers, this marker disappears." (my bold).
BEA #3 pp. 20,21.
Suffice to say that the time when this marker would be important, is when the speed window incorporates speeds (low) aroind the AoA for STALL WARN. The speeds are low because of FMC ADR rejection, so the marker is missing, just when it is imperative to be present?