Are you saying that one needs to declare also within EU? The page i linked says one needs to declare entering or leaving EU.
Even if your cash is 100% white snow :
I would not trust the link you mentionned and would dig for more official sources of infos.
I will enquiry my local Customs office (airport - harbour - land head quater). And most probably enquriy the custom at Arrival destination with EU.
Problems : some EU states/Customs will not apply EU regulations => they apply domestic regulation.
If no proof of origin of cash 100K or 1M : difficult / problem.
Once in germany, no banks will allow you to deposit such amount without proof of origin and more certified "papers" causing the purpose of the money.
In my case : I always declare over limit cash at Arrival. I prefer to spend 2 hours with Customs Agents filling forms and waiting, but clearing customs at arrival with full proof of the funds in that new territory !!!
Declaring over limit at Arrival you respect the rules, usually no problems with the Customs Agents.
Not declaring and get stopped : you did not respect the rules, then start problems with the Customs Agent.
But
If cash is BIG, + grey to dark : Italia, Germany, Fr, several unformal groups (some muslim, some from Eastern EU States) and mafia groups provide big cash travel services accross several countries/continents. I can't help....
Last 2 years was an active muslim group providing big cash travel to Casablanca - Marocco. Cash departure from EU was automaticaly landing in "shady" bank of Casa. with new hard currency bank account at your name... I can't help....