Window dressing.
The new rules allow for a 30-day voluntary departure period for illegal immigrants before their expulsion.
Hurray, 30 days to re-disappear into the undocumented society we were already in when we got caught!
France gets to keep it's appeas er policy of not really doing anything, countries are already opted out. I think that an anti-immigrant backlash will eventually set member states at odds enough to destroy the EU. Most likely an anti-muslim backlash if that follishness spills out of France and say into Germany.