As with everything 'aviation' in my long time 'doing it', I now find myself again 'surprised' that with the technology existent in ACARS, with regular position reports, a system of 'Flight Watch' was not apparently present in AF - it may be that no operator does this? We can, I think, safely say that an earlier 'alert' to the crash would not have improved survivability, but in another scenario where a semi-successful forced landing/ditching took place it could well do. As suggested here, it is not difficult to pass or extract reports from the ACARS stream, and AF ops would not be particularly busy at that time of day. AF could well have known something was amiss far earlier, or at least have been alert to watch for the next pos report.
Regarding suggestions that 'serious' events had begun well before 0200, have we not established that the Captain was not in the flight deck at this time? I don't know about other Captains, but I would have been.