That title is highly editorialized. The actual effect is just that .eu domains will have to be renewed through a registrar that's established in the EU. Most major registrars probably already fulfill that requirement, and those that don't shouldn't have any problem with founding an EU subsidiary.
EDIT: Missed the part where "Accredited
.eu
Registrars
will not be entitled to process any request for the registration of
or for renewing registrations of .eu domain names by those [UK] undertakings, organisations
and persons." Still, I bet the vast majority of domains will be transferred to some shell entity in the EU, even if it's just domain owners selling off domains they can't renew anymore.
EDIT: Missed the part where "Accredited .eu Registrars will not be entitled to process any request for the registration of or for renewing registrations of .eu domain names by those [UK] undertakings, organisations and persons." Still, I bet the vast majority of domains will be transferred to some shell entity in the EU, even if it's just domain owners selling off domains they can't renew anymore.