There is no question that the pilots would have known that they'd had a heavy landing - the de-rotation idea is nonsense.
Too much simulator time worrying about headshrinker horse**** CRM and not enough real aircraft handling, plus the current attitude of throw it on, brake hard and get off the RW fast, rather than the 'BOAC' landings required from RAF air transport pilots of the past - and which we taught our students.
Apart from 'line training' U/T pilot landings, the worst CAT landings I've experienced as a passenger were in the earlier times of the A321 when it was clear that the Airbus figures for Vref were too low. I spoke with a colleague who told me why - and that in his company they normally add at least 5 knots to the Airbus figures for the A321, which improved things significantly.
Smooth landings seem to be a thing of the past, but no amount of routine 'firm' landings could insulate pilots from knowing when they've had a very heavy landing.