Hi positionbusbo,
what does anti ice have to do with controlling pack outlet temperature..
Have a look at the diagram DSC-21-10-20 Pack Schematic (simplified) and note there is an aniti-ice valve in the system. (nothing to do with engine or wing anti-ice)
If the Pack outlet temperature is below 0 degrees C, then there is a danger of ice build up in the ducting etc. To ensure the temperature is above 0C, an anti-ice valve is fitted which can introduce hot bleed air just downstream of the pack turbine.