He's saying that this was the case, in principle, even before the refugee crisis and even when taking planes or ferries from countries other than Greece. You guys just never noticed it because you're nerds from European countries rather than being bearded turban-wearing pop-concert loving jihadi sexual predators and there wasn't such a pressing need to be particularly strict. Both temporary controls under extenuating circumstances as well as domestic laws requiring you to carry papers etc. are provided for by the agreement.