If not push, just release the backpressure
I truly doubt that FBW had anything to do with this incident
As most modern FBW aircraft do also have some sort of auto trim logic in their control system, there is no more backpressure. You really have to push to tell the computers that you want to go back to the condition you were in before you pulled. You can release the backpressure and your control system still remembers your pull command and delivers what you asked for.
Because of this, FBW has quite a lot to do with any incident/accident involving the flight controls, as it is always more than just replacing control cables with electric wires. It is a different control system requiring different flying technique. Quite similar to the difference between powered flight controls and pure mechanic ones. Backpressure on a DC-3 is quite different from backpressure on a 747...
And still, few airlines teach this in the sim.
I would not trust the sim in those situations anyway, it is far outside the range it has been developed for. For most aircraft the numbers in the sim computers will simply be extrapolated, and not resulting from flight test data.
they prefer to train to avoid the stalls in the first place.
It does however not do any harm to also train how to recover from it. First priority should of course always be avoidance. Just like CBs, terrain, traffic...
We should also remember that the regulation is not asking for spin recovery of multi engine aircraft or stall recovery of large transport aircraft. All that is required is recovery from the situation when the warning is triggered. It is not required to fly full stalls in flight testing. And matter of fact, several prototypes were lost during stall testing in the past, so it is probably wiser to avoid it altogether.