Stick Pushers and DP Davies
Davies did a long writeup on the certification requirement for stick pushers in T-tailed a/c.
The pushers were required in these a/c because the stall was unrecoverable.
Pushers are not required in a/c that can recover with standard pilot actions.
We are seeing high altitude stalls all the way to the ground and not just in Airbii - there's also at least one single engine turboprop I know of
To recover from a stall in an a/c certified as able to recover, you must first recognise it, then take appropriate corrective action.
Recognition becomes harder when the a/c settles into a steady state as with AF447 for which we do have data.
Certification requires the stall be recognisable. The nose drop has been superceded by aural warning, but as others have pointed out the human brain can shut down the auditory channel in high stress situations. I was in a simulator when the other pilot went inverted at 16,000' (white on black AH) and kept it there while I was shouting in his ear all the way to the ground.
What still bothers me about Brand A is that so far I have not heard of any test flights to determine stall behavior and recovery at any altitude.
Brand B seems to recover from high altitude stall events, but I have not come across any discussion that Brand B does stall test flights even though prevailing sentiment is that they likely do.