I'm from France so I can step in here. He's actually talking about the recent ban on the abaya, a long dress that's trending in the middle east and that some women recently started wearing here. Nothing to do with religions.

Also, the ban concerns school students, not government employees such as teachers. So even if the dress was religious, the ban wouldn't be because of "laïcité" (separation of church and state).

Actually, it would be a breach of the principle of "laïcité", because the state shouldn't be able to decide how the citizens can practice their religion. You can't have a separation of church and state, and at the same time a state that mandates which religions are good and which aren't.