? about ECU+body control module on 2005 liberty / legacy

[dv8]

ive got a australian 2005 liberty / legacy 3.0 that i need to replace the ecu on ( flood damaged car)

i went to the local subaru dealership and the mechanic reckons i need a new body control module to go with the ecu.

and says that models up to 2004 can have the body control module reprogrammed for the new ecu, but not 2005 + models.

is this true or are they incompetent ? seems strange , because if i got a new body control module and an ecu surely they would have to be coded to each other too ?

thanks mark