We called "thrust set" at 80 its to assure the correct thrust was set thus enabling us to meet the performance requirements, then the AUTOTHROTTLE SYSTEM goes into the "throttle hold" mode, which leaves the autothrottle clutches disengaged to allow further lever movement without interference from the system...
"Throttle hold" has nothing to do with any particular thrust setting, it simply puts the system in a "standby mode" so to speak during the takeoff, and other phases of flight to allow free movement of the thrust levers, without completely de-activating the auto throttle system...simple really..