Hence it recommends 5 degrees with CLB power. Totally wrong thing to do
Sorry but I disagree, 5° CLB is the pitch and power data to get you away from troubles (if the safe conduct of the flight is impacted), then you set the pitch and power from the table off the cecklist...
If you are at 39000 and loose the airspeed indication all of sudden but still level, no change of airframe noise and altitude then you go for the table without setting 5° and CLB, therefore I cannot agree with you when you say that there is no airbus checklist for unreliable speed at cruise level, there is, and to me it's quite clear.