I think it just means that they are tightening some controls, as is allowed under the Schengen accords. It's not a full abandon of the free circulation rules, but a temporary return to some controls. It's done whenever the alert plans ("vigipirate") goes to the color "red", like now. This has a lot of other consequences, like soldiers patrolling the metro, the doors to our kindergarden being locked, and a rent-a-cop in the entrance to our office building.

I wouldn't make too much of it.

In the long run, we're all dead. John Maynard Keynes