Europe's power center with respect to immigration policy isn't actually in any of the feral cities except for one: Brussels. And the decisions that affect everyday life are made by the very last people to feel their consequences. They are historically the last ones to go to the guillotine as well, but go they will.
These have no contingency plans for deporting anyone as they haven't the slightest intentions of doing so. Like all authoritarians their intention is permanent, irrevocable change.
In a best-case scenario central EU bureaucracy will fail when it can no longer enforce its edicts through the national governments, who will end up dealing with the problem with their recovered sovereignty in their own various ways. Some of those will be surrender. Some will be violence.
There is a certain sadness that a Europe freed from the tensions of the Cold War has found, through its rulers, a way to indulge in the killing again. A number of commentators on geostrategy have speculated on what it all will look like when Pax Americana ends. We're about to find out.
Just an observation:
I find it interesting that neither the author nor anyone who’s commented thus far has mentioned the underlying issue at hand (IMHO): The New Caliphate.
https://rairfoundation.com/rise-new-caliphate-europe-faces-growing-jihadist-threat/