This indicates that the autopilot has been automatically switched off
Perhaps answers your question?
Mayday
Yes, it would be expected, with some provisos
Drowning
When an a/c impacts very hard (and it seems likely it did) the cause of death would invariably be physical trauma of one sort or another. Thus it is not unexpected that drowning would not take place (in the majority of cases anyway).
NB. There could be more deductions to come with the full autopsy reports
Incapacitation
I also 'feel' that insufficient information is yet available to completely rule out some sort of crew incapacitation, but such suggestions will no doubt encourage (& have) dismissal or flak here...
The reason for this is it has to be said, with autopilot off, and no-one flying the a/c, it might be expected that from cruise altitude it would exceed speed/structural limits long before arriving at sea level - and - BEA (French accident investigation authority) and many here think that it was probably in one piece at the time of impact.
Recap:
The last ascertain(ed) crew action appears to have been at 2.01 hrs - a 3rd attempt to contact DAKAR control, approx 9 minutes before that A/P disconnect msg. I think we have it on good authority that this couldn't have been a pre-programmed action.
Speculation:
The a/c entered heavy turbulence (probably for the first time) between 2.01 and 2.10 hrs.
Additionally:
The a/c seems to have been apprpx. 3 nm West of expected track at 2.10 hrs. This could have been a deliberate action or the result of a prior disturbance