I'm sure it is being discussed in high places right now .
At the moment, they are lots of ways to monitor a flight in remote places, but they all assume that the crew is in control and able to operate those systems.
HF, ACARS, SATCOM, CPDLC, ADS, ELT, to name most of them.
The Emergency Locator Transmitter doesn't need aircraft electrical power and can be activated at anytime by the crew from the cockpit. It will also transmit after a high-G impact, but is unlikely to survive a high energy event.
Nobody placed a telephone call from the cabin through SATCOM, pointing to a sudden event, assuming the 777 was equipped with such a facility.