With all the 'confirm' assumptions and concurrence that ACARS was deliberately disabled, wouldn't it be a possible scenario that the C/B's for VHF2 and 3 were pulled, and ACARS happen to transmit via VHF3?
And if it is a deliberate (i.e. hijack/suicide) action, I would want to keep VHF1 and HF1 alive to monitor radio chatter.