Would a return to national regulations require an initial Class1 for every int´l job?
 

Pardon the speculative nature of my question, but maybe those of you who have flown pre-EASA may remember what it was like to work internationally back then:

Assuming that pilots always will take up work outside of their own country, what would happen to licenses, medicals etc. if the EU is weakened or restructured as a result of the COVID crisis, triggering a return to national regulations or other de-harmonisation? Say, a Dutch pilots trains in Spain(1), spends his first years building hours on a TP in Germany(2), then secures his first jet job in the UK(3) and finally manages to return home(4) as a KLM skipper. In pre-EASA years, and maybe in a future scenario, would this guy have to do 4 initial Class 1 and additional exams for every job during his career?