Hi @ngidzak

It's in the same preference file as the iCloud stuff in a key called DidSeeSiriSetup.

We've used the defaults command to set it but a config profile would probably also work:

for USER_TEMPLATE in "/System/Library/User Template"/*
  do
    /usr/bin/defaults write "${USER_TEMPLATE}"/Library/Preferences/com.apple.SetupAssistant DidSeeSiriSetup -bool TRUE
  done

Just setup a profile for this. Works great!