I'm nevertheless still unclear about the bottom line as you see it.
Maybe because I was careful not to give a bottom line
do you consider, on an aerodynamic basis, that the A330 is actually likely to be recoverable from even a ~60-degree AoA magnitude of stall upset, given some other set of control inputs [i.e. besides maintaining max NU on the SS until altitude is exhausted]?
Certainly not from the altitude at which they seem to have arrived at that AoA!
If they had had enough altitude then maybe yes, but they would have to have done it carefully. We know, or at least we think we know, that they were at something more like 40 deg AoA for a lot of the descent, so by my reckoning they could have got back that far just by relaxing on the stick. The problem with a more aggressive recovery from 60 deg is that if they tried to apply any significant nose down elevator when at that AoA they might have stalled the THS as DJ77 suggests. This would have screwed things up mightily.
If they had first got back to 40 deg, or indeed if they had started recovery from 40 deg or thereabouts in the first place then, again as DJ77 says, the THS AoA would be body AoA minus downwash minus THS setting - say about 40-20-13 = 7 deg. There wouldn't be any problem applying down elevator from that sort of AoA, so they should have been able to pitch the nose down far enough to get out of stalled conditions, accelerate a bit and initiate a pull up. Trouble is, that process would eat up several tens of thousands of feet in altitude, so unless they recognised the situation and started recovery early they were always going to be in danger of not being able to recover before they hit the sea.