The main problem with the MH370 disappearance was that the response to a missing aircraft has not altered for years. Aircraft overdue action is only legitimate once the aircraft is overdue at destination. In the current systems where aircraft are already continually tracked - despite the avionics and comms salesmen claims - an aircraft ceasing to report its position and respond to RT/CPDLC should immediately be treated as an emergency. Even with the loss of secondary being on handoff, the systems could have flagged a possible problem. The Malaysian and Vietnamese controllers should then both have treated the missing aircraft as an emergency and alerted all agencies including the military. The military would almost certainly have responded that they could still 'see' the aircraft. The event could then have had an entirely different outcome.
There is no need for new equipment to track aircraft they all have it. The beancounters try to limit the use of ADS-C as the SATCOM providers charge for each transmission. However, that is no longer the case as both INMARSAT and AIREON (Iridium Next) are offering free tracking services. With AIREON also proposing to track ADS-B (although the capability is yet to be proven). What is needed is procedures to use when the tracking suddenly fails because the aircraft has 'gone dark'.
I would propose that someone at the ICAO level start's looking at the old procedures for missing/overdue aircraft. A start would be an immediate response to aircraft that stop communicating/transponding rather than we wait for the end of the aircraft endurance before we can start anything official.